patch, 11 partsgitweb: Change timezone

.gitignore, gitweb/Makefile, gitweb/static/js/README, gitweb/static/gitweb.js, gitweb/static/js/blame_incremental.js, gitweb/static/js/javascript-detection.js, gitweb/static/js/lib/common-lib.js

diff --git a/.gitignore b/.gitignore
index 2cf3ca5..9e95005 100644
--- a/.gitignore
+++ b/.gitignore
@@ -158,6 +158,7 @@
 /gitk-git/gitk-wish
 /gitweb/GITWEB-BUILD-OPTIONS
 /gitweb/gitweb.cgi
+/gitweb/static/gitweb.js
 /gitweb/static/gitweb.min.*
 /test-chmtime
 /test-ctype
diff --git a/gitweb/Makefile b/gitweb/Makefile
index 0a6ac00..0baa9df 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -86,7 +86,7 @@ ifndef V
 endif
 endif
 
-all:: gitweb.cgi
+all:: gitweb.cgi static/gitweb.js
 
 GITWEB_PROGRAMS = gitweb.cgi
 
@@ -112,6 +112,15 @@ endif
 
 GITWEB_FILES += static/git-logo.png static/git-favicon.png
 
+# JavaScript files that are composed (concatenated) to form gitweb.js
+#
+# js/lib/common-lib.js should be always first, then js/lib/*.js,
+# then the rest of files; js/gitweb.js should be last (if it exists)
+GITWEB_JSLIB_FILES += static/js/lib/common-lib.js
+GITWEB_JSLIB_FILES += static/js/javascript-detection.js
+GITWEB_JSLIB_FILES += static/js/blame_incremental.js
+
+
 GITWEB_REPLACE = \
 	-e 's|++GIT_VERSION++|$(GIT_VERSION)|g' \
 	-e 's|++GIT_BINDIR++|$(bindir)|g' \
@@ -146,6 +155,11 @@ gitweb.cgi: gitweb.perl GITWEB-BUILD-OPTIONS
 	chmod +x $@+ && \
 	mv $@+ $@
 
+static/gitweb.js: $(GITWEB_JSLIB_FILES)
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	cat $^ >$@+ && \
+	mv $@+ $@
+
 ### Testing rules
 
 test:
diff --git a/gitweb/static/js/README b/gitweb/static/js/README
new file mode 100644
index 0000000..f8460ed
--- /dev/null
+++ b/gitweb/static/js/README
@@ -0,0 +1,20 @@
+GIT web interface (gitweb) - JavaScript
+=======================================
+
+This directory holds JavaScript code used by gitweb (GIT web interface).
+Scripts from there would be concatenated together in the order specified
+by gitweb/Makefile into gitweb/static/gitweb.js, during building of
+gitweb/gitweb.cgi (during gitweb building).  The resulting file (or its
+minification) would then be installed / deployed together with gitweb.
+
+Scripts in 'lib/' subdirectory compose generic JavaScript library,
+providing features required by gitweb but in no way limited to gitweb
+only.  In the future those scripts could be replaced by some JavaScript
+library / framework, like e.g. jQuery, YUI, Prototype, MooTools, Dojo,
+ExtJS, Script.aculo.us or SproutCore.
+
+All scripts that manipulate gitweb output should be put outside 'lib/',
+directly in this directory ('gitweb/static/js/').  Those scripts would
+have to be rewritten if gitweb moves to using some JavaScript library.
+
+See also comments in gitweb/Makefile.
diff --git a/gitweb/static/gitweb.js b/gitweb/static/js/blame_incremental.js
similarity index 76%
rename from gitweb/static/gitweb.js
rename to gitweb/static/js/blame_incremental.js
index 40ec084..f63f78b 100644
--- a/gitweb/static/gitweb.js
+++ b/gitweb/static/js/blame_incremental.js
@@ -1,44 +1,12 @@
 // Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
 //               2007, Petr Baudis <pasky@suse.cz>
-//          2008-2009, Jakub Narebski <jnareb@gmail.com>
+//          2008-2011, Jakub Narebski <jnareb@gmail.com>
 
 /**
- * @fileOverview JavaScript code for gitweb (git web interface).
+ * @fileOverview JavaScript side of Ajax-y 'blame_incremental' view in gitweb
  * @license GPLv2 or later
  */
 
-/* ============================================================ */
-/* functions for generic gitweb actions and views */
-
-/**
- * used to check if link has 'js' query parameter already (at end),
- * and other reasons to not add 'js=1' param at the end of link
- * @constant
- */
-var jsExceptionsRe = /[;?]js=[01]$/;
-
-/**
- * Add '?js=1' or ';js=1' to the end of every link in the document
- * that doesn't have 'js' query parameter set already.
- *
- * Links with 'js=1' lead to JavaScript version of given action, if it
- * exists (currently there is only 'blame_incremental' for 'blame')
- *
- * @globals jsExceptionsRe
- */
-function fixLinks() {
-	var allLinks = document.getElementsByTagName("a") || document.links;
-	for (var i = 0, len = allLinks.length; i < len; i++) {
-		var link = allLinks[i];
-		if (!jsExceptionsRe.test(link)) { // =~ /[;?]js=[01]$/;
-			link.href +=
-				(link.href.indexOf('?') === -1 ? '?' : ';') + 'js=1';
-		}
-	}
-}
-
-
-/* ============================================================ */
 
 /*
  * This code uses DOM methods instead of (nonstandard) innerHTML
@@ -59,71 +27,6 @@ function fixLinks() {
 
 
 /* ============================================================ */
-/* generic utility functions */
-
-
-/**
- * pad number N with nonbreakable spaces on the left, to WIDTH characters
- * example: padLeftStr(12, 3, '\u00A0') == '\u00A012'
- *          ('\u00A0' is nonbreakable space)
- *
- * @param {Number|String} input: number to pad
- * @param {Number} width: visible width of output
- * @param {String} str: string to prefix to string, e.g. '\u00A0'
- * @returns {String} INPUT prefixed with (WIDTH - INPUT.length) x STR
- */
-function padLeftStr(input, width, str) {
-	var prefix = '';
-
-	width -= input.toString().length;
-	while (width > 0) {
-		prefix += str;
-		width--;
-	}
-	return prefix + input;
-}
-
-/**
- * Pad INPUT on the left to SIZE width, using given padding character CH,
- * for example padLeft('a', 3, '_') is '__a'.
- *
- * @param {String} input: input value converted to string.
- * @param {Number} width: desired length of output.
- * @param {String} ch: single character to prefix to string.
- *
- * @returns {String} Modified string, at least SIZE length.
- */
-function padLeft(input, width, ch) {
-	var s = input + "";
-	while (s.length < width) {
-		s = ch + s;
-	}
-	return s;
-}
-
-/**
- * Create XMLHttpRequest object in cross-browser way
- * @returns XMLHttpRequest object, or null
- */
-function createRequestObject() {
-	try {
-		return new XMLHttpRequest();
-	} catch (e) {}
-	try {
-		return window.createRequest();
-	} catch (e) {}
-	try {
-		return new ActiveXObject("Msxml2.XMLHTTP");
-	} catch (e) {}
-	try {
-		return new ActiveXObject("Microsoft.XMLHTTP");
-	} catch (e) {}
-
-	return null;
-}
-
-
-/* ============================================================ */
 /* utility/helper functions (and variables) */
 
 var xhr;        // XMLHttpRequest object
@@ -392,111 +295,6 @@ function fixColorsAndGroups() {
 	}
 }
 
-/* ............................................................ */
-/* time and data */
-
-/**
- * used to extract hours and minutes from timezone info, e.g '-0900'
- * @constant
- */
-var tzRe = /^([+-])([0-9][0-9])([0-9][0-9])$/;
-
-/**
- * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
- *
- * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
- * @returns {Number} offset from UTC in seconds for timezone
- *
- * @globals tzRe
- */
-function timezoneOffset(timezoneInfo) {
-	var match = tzRe.exec(timezoneInfo);
-	var tz_sign = (match[1] === '-' ? -1 : +1);
-	var tz_hour = parseInt(match[2],10);
-	var tz_min  = parseInt(match[3],10);
-
-	return tz_sign*(((tz_hour*60) + tz_min)*60);
-}
-
-/**
- * return date in local time formatted in iso-8601 like format
- * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
- *
- * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
- * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
- * @returns {String} date in local time in iso-8601 like format
- */
-function formatDateISOLocal(epoch, timezoneInfo) {
-	// date corrected by timezone
-	var localDate = new Date(1000 * (epoch +
-		timezoneOffset(timezoneInfo)));
-	var localDateStr = // e.g. '2005-08-07'
-		localDate.getUTCFullYear()                 + '-' +
-		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
-		padLeft(localDate.getUTCDate(),    2, '0');
-	var localTimeStr = // e.g. '21:49:46'
-		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
-		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
-		padLeft(localDate.getUTCSeconds(), 2, '0');
-
-	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
-}
-
-/* ............................................................ */
-/* unquoting/unescaping filenames */
-
-/**#@+
- * @constant
- */
-var escCodeRe = /\\([^0-7]|[0-7]{1,3})/g;
-var octEscRe = /^[0-7]{1,3}$/;
-var maybeQuotedRe = /^\"(.*)\"$/;
-/**#@-*/
-
-/**
- * unquote maybe git-quoted filename
- * e.g. 'aa' -> 'aa', '"a\ta"' -> 'a	a'
- *
- * @param {String} str: git-quoted string
- * @returns {String} Unquoted and unescaped string
- *
- * @globals escCodeRe, octEscRe, maybeQuotedRe
- */
-function unquote(str) {
-	function unq(seq) {
-		var es = {
-			// character escape codes, aka escape sequences (from C)
-			// replacements are to some extent JavaScript specific
-			t: "\t",   // tab            (HT, TAB)
-			n: "\n",   // newline        (NL)
-			r: "\r",   // return         (CR)
-			f: "\f",   // form feed      (FF)
-			b: "\b",   // backspace      (BS)
-			a: "\x07", // alarm (bell)   (BEL)
-			e: "\x1B", // escape         (ESC)
-			v: "\v"    // vertical tab   (VT)
-		};
-
-		if (seq.search(octEscRe) !== -1) {
-			// octal char sequence
-			return String.fromCharCode(parseInt(seq, 8));
-		} else if (seq in es) {
-			// C escape sequence, aka character escape code
-			return es[seq];
-		}
-		// quoted ordinary character
-		return seq;
-	}
-
-	var match = str.match(maybeQuotedRe);
-	if (match) {
-		str = match[1];
-		// perhaps str = eval('"'+str+'"'); would be enough?
-		str = str.replace(escCodeRe,
-			function (substr, p1, offset, s) { return unq(p1); });
-	}
-	return str;
-}
 
 /* ============================================================ */
 /* main part: parsing response */
@@ -886,4 +684,4 @@ function startBlame(blamedataUrl, bUrl) {
 	pollTimer = setInterval(xhr.onreadystatechange, 1000);
 }
 
-// end of gitweb.js
+/* end of blame_incremental.js */
diff --git a/gitweb/static/js/javascript-detection.js b/gitweb/static/js/javascript-detection.js
new file mode 100644
index 0000000..93dd2bd
--- /dev/null
+++ b/gitweb/static/js/javascript-detection.js
@@ -0,0 +1,43 @@
+// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
+//               2007, Petr Baudis <pasky@suse.cz>
+//          2008-2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview Detect if JavaScript is enabled, and pass it to server-side
+ * @license GPLv2 or later
+ */
+
+
+/* ============================================================ */
+/* Manipulating links */
+
+/**
+ * used to check if link has 'js' query parameter already (at end),
+ * and other reasons to not add 'js=1' param at the end of link
+ * @constant
+ */
+var jsExceptionsRe = /[;?]js=[01]$/;
+
+/**
+ * Add '?js=1' or ';js=1' to the end of every link in the document
+ * that doesn't have 'js' query parameter set already.
+ *
+ * Links with 'js=1' lead to JavaScript version of given action, if it
+ * exists (currently there is only 'blame_incremental' for 'blame')
+ *
+ * To be used as `window.onload` handler
+ *
+ * @globals jsExceptionsRe
+ */
+function fixLinks() {
+	var allLinks = document.getElementsByTagName("a") || document.links;
+	for (var i = 0, len = allLinks.length; i < len; i++) {
+		var link = allLinks[i];
+		if (!jsExceptionsRe.test(link)) { // =~ /[;?]js=[01]$/;
+			link.href +=
+				(link.href.indexOf('?') === -1 ? '?' : ';') + 'js=1';
+		}
+	}
+}
+
+/* end of javascript-detection.js */
diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
new file mode 100644
index 0000000..38f3b9e
--- /dev/null
+++ b/gitweb/static/js/lib/common-lib.js
@@ -0,0 +1,187 @@
+// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
+//               2007, Petr Baudis <pasky@suse.cz>
+//          2008-2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview Generic JavaScript code (helper functions)
+ * @license GPLv2 or later
+ */
+
+
+/* ============================================================ */
+/* ............................................................ */
+/* Padding */
+
+/**
+ * pad number N with nonbreakable spaces on the left, to WIDTH characters
+ * example: padLeftStr(12, 3, '\u00A0') == '\u00A012'
+ *          ('\u00A0' is nonbreakable space)
+ *
+ * @param {Number|String} input: number to pad
+ * @param {Number} width: visible width of output
+ * @param {String} str: string to prefix to string, e.g. '\u00A0'
+ * @returns {String} INPUT prefixed with (WIDTH - INPUT.length) x STR
+ */
+function padLeftStr(input, width, str) {
+	var prefix = '';
+
+	width -= input.toString().length;
+	while (width > 0) {
+		prefix += str;
+		width--;
+	}
+	return prefix + input;
+}
+
+/**
+ * Pad INPUT on the left to SIZE width, using given padding character CH,
+ * for example padLeft('a', 3, '_') is '__a'.
+ *
+ * @param {String} input: input value converted to string.
+ * @param {Number} width: desired length of output.
+ * @param {String} ch: single character to prefix to string.
+ *
+ * @returns {String} Modified string, at least SIZE length.
+ */
+function padLeft(input, width, ch) {
+	var s = input + "";
+	while (s.length < width) {
+		s = ch + s;
+	}
+	return s;
+}
+
+
+/* ............................................................ */
+/* Ajax */
+
+/**
+ * Create XMLHttpRequest object in cross-browser way
+ * @returns XMLHttpRequest object, or null
+ */
+function createRequestObject() {
+	try {
+		return new XMLHttpRequest();
+	} catch (e) {}
+	try {
+		return window.createRequest();
+	} catch (e) {}
+	try {
+		return new ActiveXObject("Msxml2.XMLHTTP");
+	} catch (e) {}
+	try {
+		return new ActiveXObject("Microsoft.XMLHTTP");
+	} catch (e) {}
+
+	return null;
+}
+
+
+/* ............................................................ */
+/* time and data */
+
+/**
+ * used to extract hours and minutes from timezone info, e.g '-0900'
+ * @constant
+ */
+var tzRe = /^([+-])([0-9][0-9])([0-9][0-9])$/;
+
+/**
+ * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
+ *
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {Number} offset from UTC in seconds for timezone
+ *
+ * @globals tzRe
+ */
+function timezoneOffset(timezoneInfo) {
+	var match = tzRe.exec(timezoneInfo);
+	var tz_sign = (match[1] === '-' ? -1 : +1);
+	var tz_hour = parseInt(match[2],10);
+	var tz_min  = parseInt(match[3],10);
+
+	return tz_sign*(((tz_hour*60) + tz_min)*60);
+}
+
+/**
+ * return date in local time formatted in iso-8601 like format
+ * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
+ *
+ * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {String} date in local time in iso-8601 like format
+ */
+function formatDateISOLocal(epoch, timezoneInfo) {
+	// date corrected by timezone
+	var localDate = new Date(1000 * (epoch +
+		timezoneOffset(timezoneInfo)));
+	var localDateStr = // e.g. '2005-08-07'
+		localDate.getUTCFullYear()                 + '-' +
+		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
+		padLeft(localDate.getUTCDate(),    2, '0');
+	var localTimeStr = // e.g. '21:49:46'
+		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
+		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
+		padLeft(localDate.getUTCSeconds(), 2, '0');
+
+	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
+}
+
+
+/* ............................................................ */
+/* unquoting/unescaping filenames */
+
+/**#@+
+ * @constant
+ */
+var escCodeRe = /\\([^0-7]|[0-7]{1,3})/g;
+var octEscRe = /^[0-7]{1,3}$/;
+var maybeQuotedRe = /^\"(.*)\"$/;
+/**#@-*/
+
+/**
+ * unquote maybe git-quoted filename
+ * e.g. 'aa' -> 'aa', '"a\ta"' -> 'a	a'
+ *
+ * @param {String} str: git-quoted string
+ * @returns {String} Unquoted and unescaped string
+ *
+ * @globals escCodeRe, octEscRe, maybeQuotedRe
+ */
+function unquote(str) {
+	function unq(seq) {
+		var es = {
+			// character escape codes, aka escape sequences (from C)
+			// replacements are to some extent JavaScript specific
+			t: "\t",   // tab            (HT, TAB)
+			n: "\n",   // newline        (NL)
+			r: "\r",   // return         (CR)
+			f: "\f",   // form feed      (FF)
+			b: "\b",   // backspace      (BS)
+			a: "\x07", // alarm (bell)   (BEL)
+			e: "\x1B", // escape         (ESC)
+			v: "\v"    // vertical tab   (VT)
+		};
+
+		if (seq.search(octEscRe) !== -1) {
+			// octal char sequence
+			return String.fromCharCode(parseInt(seq, 8));
+		} else if (seq in es) {
+			// C escape sequence, aka character escape code
+			return es[seq];
+		}
+		// quoted ordinary character
+		return seq;
+	}
+
+	var match = str.match(maybeQuotedRe);
+	if (match) {
+		str = match[1];
+		// perhaps str = eval('"'+str+'"'); would be enough?
+		str = str.replace(escCodeRe,
+			function (substr, p1, offset, s) { return unq(p1); });
+	}
+	return str;
+}
+
+/* end of common-lib.js */

gitweb/static/js/blame_incremental.js, gitweb/static/js/lib/common-lib.js

diff --git a/gitweb/static/js/blame_incremental.js b/gitweb/static/js/blame_incremental.js
index f63f78b..676da6b 100644
--- a/gitweb/static/js/blame_incremental.js
+++ b/gitweb/static/js/blame_incremental.js
@@ -7,7 +7,7 @@
  * @license GPLv2 or later
  */
 
-
+/* ============================================================ */
 /*
  * This code uses DOM methods instead of (nonstandard) innerHTML
  * to modify page.
@@ -26,7 +26,7 @@
  */
 
 
-/* ============================================================ */
+/* ............................................................ */
 /* utility/helper functions (and variables) */
 
 var xhr;        // XMLHttpRequest object
@@ -132,7 +132,7 @@ function writeTimeInterval() {
 }
 
 /**
- * show an error message alert to user within page (in prohress info area)
+ * show an error message alert to user within page (in progress info area)
  * @param {String} str: plain text error message (no HTML)
  *
  * @globals div_progress_info
@@ -182,7 +182,7 @@ function getColorNo(tr) {
 
 var colorsFreq = [0, 0, 0];
 /**
- * return one of given possible colors (curently least used one)
+ * return one of given possible colors (currently least used one)
  * example: chooseColorNoFrom(2, 3) returns 2 or 3
  *
  * @param {Number[]} arguments: one or more numbers
@@ -203,8 +203,8 @@ function chooseColorNoFrom() {
 }
 
 /**
- * given two neigbour <tr> elements, find color which would be different
- * from color of both of neighbours; used to 3-color blame table
+ * given two neighbor <tr> elements, find color which would be different
+ * from color of both of neighbors; used to 3-color blame table
  *
  * @param {HTMLElement} tr_prev
  * @param {HTMLElement} tr_next
@@ -216,14 +216,14 @@ function findColorNo(tr_prev, tr_next) {
 	var color_next = getColorNo(tr_next);
 
 
-	// neither of neighbours has color set
+	// neither of neighbors has color set
 	// THEN we can use any of 3 possible colors
 	if (!color_prev && !color_next) {
 		return chooseColorNoFrom(1,2,3);
 	}
 
-	// either both neighbours have the same color,
-	// or only one of neighbours have color set
+	// either both neighbors have the same color,
+	// or only one of neighbors have color set
 	// THEN we can use any color except given
 	var color;
 	if (color_prev === color_next) {
@@ -237,7 +237,7 @@ function findColorNo(tr_prev, tr_next) {
 		return chooseColorNoFrom((color % 3) + 1, ((color+1) % 3) + 1);
 	}
 
-	// neighbours have different colors
+	// neighbors have different colors
 	// THEN there is only one color left
 	return (3 - ((color_prev + color_next) % 3));
 }
@@ -258,7 +258,7 @@ function isStartOfGroup(tr) {
 
 /**
  * change colors to use zebra coloring (2 colors) instead of 3 colors
- * concatenate neighbour commit groups belonging to the same commit
+ * concatenate neighbor commit groups belonging to the same commit
  *
  * @globals colorRe
  */
diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index 38f3b9e..6a6d200 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -13,14 +13,17 @@
 /* Padding */
 
 /**
- * pad number N with nonbreakable spaces on the left, to WIDTH characters
+ * pad INPUT on the left with STR that is assumed to have visible
+ * width of single character (for example nonbreakable spaces),
+ * to WIDTH characters
+ *
  * example: padLeftStr(12, 3, '\u00A0') == '\u00A012'
  *          ('\u00A0' is nonbreakable space)
  *
  * @param {Number|String} input: number to pad
  * @param {Number} width: visible width of output
  * @param {String} str: string to prefix to string, e.g. '\u00A0'
- * @returns {String} INPUT prefixed with (WIDTH - INPUT.length) x STR
+ * @returns {String} INPUT prefixed with STR x (WIDTH - INPUT.length)
  */
 function padLeftStr(input, width, str) {
 	var prefix = '';
@@ -34,7 +37,7 @@ function padLeftStr(input, width, str) {
 }
 
 /**
- * Pad INPUT on the left to SIZE width, using given padding character CH,
+ * Pad INPUT on the left to WIDTH, using given padding character CH,
  * for example padLeft('a', 3, '_') is '__a'.
  *
  * @param {String} input: input value converted to string.
@@ -140,7 +143,8 @@ var maybeQuotedRe = /^\"(.*)\"$/;
 /**#@-*/
 
 /**
- * unquote maybe git-quoted filename
+ * unquote maybe C-quoted filename (as used by git, i.e. it is
+ * in double quotes '"' if there is any escape character used)
  * e.g. 'aa' -> 'aa', '"a\ta"' -> 'a	a'
  *
  * @param {String} str: git-quoted string

diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index 6a6d200..c45454e 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -22,11 +22,14 @@
  *
  * @param {Number|String} input: number to pad
  * @param {Number} width: visible width of output
- * @param {String} str: string to prefix to string, e.g. '\u00A0'
+ * @param {String} str: string to prefix to string, defaults to '\u00A0'
  * @returns {String} INPUT prefixed with STR x (WIDTH - INPUT.length)
  */
 function padLeftStr(input, width, str) {
 	var prefix = '';
+	if (typeof str === 'undefined') {
+		ch = '\u00A0'; // using ' ' doesn't work in all browsers
+	}
 
 	width -= input.toString().length;
 	while (width > 0) {
@@ -38,16 +41,21 @@ function padLeftStr(input, width, str) {
 
 /**
  * Pad INPUT on the left to WIDTH, using given padding character CH,
- * for example padLeft('a', 3, '_') is '__a'.
+ * for example padLeft('a', 3, '_') is '__a'
+ *             padLeft(4, 2) is '04' (same as padLeft(4, 2, '0'))
  *
  * @param {String} input: input value converted to string.
  * @param {Number} width: desired length of output.
- * @param {String} ch: single character to prefix to string.
+ * @param {String} ch: single character to prefix to string, defaults to '0'.
  *
  * @returns {String} Modified string, at least SIZE length.
  */
 function padLeft(input, width, ch) {
 	var s = input + "";
+	if (typeof ch === 'undefined') {
+		ch = '0';
+	}
+
 	while (s.length < width) {
 		s = ch + s;
 	}

gitweb/Makefile, gitweb/static/js/lib/common-lib.js, gitweb/static/js/lib/datetime.js

diff --git a/gitweb/Makefile b/gitweb/Makefile
index 0baa9df..403265a 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -117,6 +117,7 @@ GITWEB_FILES += static/git-logo.png static/git-favicon.png
 # js/lib/common-lib.js should be always first, then js/lib/*.js,
 # then the rest of files; js/gitweb.js should be last (if it exists)
 GITWEB_JSLIB_FILES += static/js/lib/common-lib.js
+GITWEB_JSLIB_FILES += static/js/lib/datetime.js
 GITWEB_JSLIB_FILES += static/js/javascript-detection.js
 GITWEB_JSLIB_FILES += static/js/blame_incremental.js
 
diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index c45454e..d6b0c0d 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -89,57 +89,6 @@ function createRequestObject() {
 
 
 /* ............................................................ */
-/* time and data */
-
-/**
- * used to extract hours and minutes from timezone info, e.g '-0900'
- * @constant
- */
-var tzRe = /^([+-])([0-9][0-9])([0-9][0-9])$/;
-
-/**
- * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
- *
- * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
- * @returns {Number} offset from UTC in seconds for timezone
- *
- * @globals tzRe
- */
-function timezoneOffset(timezoneInfo) {
-	var match = tzRe.exec(timezoneInfo);
-	var tz_sign = (match[1] === '-' ? -1 : +1);
-	var tz_hour = parseInt(match[2],10);
-	var tz_min  = parseInt(match[3],10);
-
-	return tz_sign*(((tz_hour*60) + tz_min)*60);
-}
-
-/**
- * return date in local time formatted in iso-8601 like format
- * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
- *
- * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
- * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
- * @returns {String} date in local time in iso-8601 like format
- */
-function formatDateISOLocal(epoch, timezoneInfo) {
-	// date corrected by timezone
-	var localDate = new Date(1000 * (epoch +
-		timezoneOffset(timezoneInfo)));
-	var localDateStr = // e.g. '2005-08-07'
-		localDate.getUTCFullYear()                 + '-' +
-		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
-		padLeft(localDate.getUTCDate(),    2, '0');
-	var localTimeStr = // e.g. '21:49:46'
-		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
-		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
-		padLeft(localDate.getUTCSeconds(), 2, '0');
-
-	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
-}
-
-
-/* ............................................................ */
 /* unquoting/unescaping filenames */
 
 /**#@+
diff --git a/gitweb/static/js/lib/datetime.js b/gitweb/static/js/lib/datetime.js
new file mode 100644
index 0000000..b3dcedb
--- /dev/null
+++ b/gitweb/static/js/lib/datetime.js
@@ -0,0 +1,161 @@
+// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
+//               2007, Petr Baudis <pasky@suse.cz>
+//          2008-2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview Datetime manipulation: parsing and formatting
+ * @license GPLv2 or later
+ */
+
+
+/* ............................................................ */
+/* parsing and retrieving datetime related information */
+
+/**
+ * used to extract hours and minutes from timezone info, e.g '-0900'
+ * @constant
+ */
+var tzRe = /^([+\-])([0-9][0-9])([0-9][0-9])$/;
+
+/**
+ * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
+ *
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {Number} offset from UTC in seconds for timezone
+ *
+ * @globals tzRe
+ */
+function timezoneOffset(timezoneInfo) {
+	var match = tzRe.exec(timezoneInfo);
+	var tz_sign = (match[1] === '-' ? -1 : +1);
+	var tz_hour = parseInt(match[2],10);
+	var tz_min  = parseInt(match[3],10);
+
+	return tz_sign*(((tz_hour*60) + tz_min)*60);
+}
+
+/**
+ * return local (browser) timezone as offset from UTC in seconds
+ *
+ * @returns {Number} offset from UTC in seconds for local timezone
+ */
+function localTimezoneOffset() {
+	// getTimezoneOffset returns the time-zone offset from UTC,
+	// in _minutes_, for the current locale
+	return ((new Date()).getTimezoneOffset() * -60);
+}
+
+/**
+ * return local (browser) timezone as numeric timezone '(+|-)HHMM'
+ *
+ * @returns {String} locat timezone as -/+ZZZZ
+ */
+function localTimezoneInfo() {
+	var tzOffsetMinutes = (new Date()).getTimezoneOffset() * -1;
+
+	return formatTimezoneInfo(0, tzOffsetMinutes);
+}
+
+
+/**
+ * Parse RFC-2822 date into a Unix timestamp (into epoch)
+ *
+ * @param {String} date: date in RFC-2822 format, e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
+ * @returns {Number} epoch i.e. seconds since '00:00:00 1970-01-01 UTC'
+ */
+function parseRFC2822Date(date) {
+	// Date.parse accepts the IETF standard (RFC 1123 Section 5.2.14 and elsewhere)
+	// date syntax, which is defined in RFC 2822 (obsoletes RFC 822)
+	// and returns number of _milli_seconds since January 1, 1970, 00:00:00 UTC
+	return Date.parse(date) / 1000;
+}
+
+
+/* ............................................................ */
+/* formatting date */
+
+/**
+ * format timezone offset as numerical timezone '(+|-)HHMM' or '(+|-)HH:MM'
+ *
+ * @param {Number} hours:    offset in hours, e.g. 2 for '+0200'
+ * @param {Number} [minutes] offset in minutes, e.g. 30 for '-4030';
+ *                           it is split into hours if not 0 <= minutes < 60,
+ *                           for example 1200 would give '+0100';
+ *                           defaults to 0
+ * @param {String} [sep] separator between hours and minutes part,
+ *                       default is '', might be ':' for W3CDTF (rfc-3339)
+ * @returns {String} timezone in '(+|-)HHMM' or '(+|-)HH:MM' format
+ */
+function formatTimezoneInfo(hours, minutes, sep) {
+	minutes = minutes || 0; // to be able to use formatTimezoneInfo(hh)
+	sep = sep || ''; // default format is +/-ZZZZ
+
+	if (minutes < 0 || minutes > 59) {
+		hours = minutes > 0 ? Math.floor(minutes / 60) : Math.ceil(minutes / 60);
+		minutes = Math.abs(minutes - 60*hours); // sign of minutes is sign of hours
+		// NOTE: this works correctly because there is no UTC-00:30 timezone
+	}
+
+	var tzSign = hours >= 0 ? '+' : '-';
+	if (hours < 0) {
+		hours = -hours; // sign is stored in tzSign
+	}
+
+	return tzSign + padLeft(hours, 2, '0') + sep + padLeft(minutes, 2, '0');
+}
+
+/**
+ * return date in local time formatted in iso-8601 like format
+ * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
+ *
+ * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {String} date in local time in iso-8601 like format
+ */
+function formatDateISOLocal(epoch, timezoneInfo) {
+	// date corrected by timezone
+	var localDate = new Date(1000 * (epoch +
+		timezoneOffset(timezoneInfo)));
+	var localDateStr = // e.g. '2005-08-07'
+		localDate.getUTCFullYear()                 + '-' +
+		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
+		padLeft(localDate.getUTCDate(),    2, '0');
+	var localTimeStr = // e.g. '21:49:46'
+		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
+		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
+		padLeft(localDate.getUTCSeconds(), 2, '0');
+
+	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
+}
+
+/**
+ * return date in local time formatted in rfc-2822 format
+ * e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
+ *
+ * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @param {Boolean} [padDay] e.g. 'Sun, 07 Aug' if true, 'Sun, 7 Aug' otherwise
+ * @returns {String} date in local time in rfc-2822 format
+ */
+function formatDateRFC2882(epoch, timezoneInfo, padDay) {
+	// A short textual representation of a month, three letters
+	var months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
+	// A textual representation of a day, three letters
+	var days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
+	// date corrected by timezone
+	var localDate = new Date(1000 * (epoch +
+		timezoneOffset(timezoneInfo)));
+	var localDateStr = // e.g. 'Sun, 7 Aug 2005' or 'Sun, 07 Aug 2005'
+		days[localDate.getUTCDay()] + ', ' +
+		(padDay ? padLeft(localDate.getUTCDate(),2,'0') : localDate.getUTCDate()) + ' ' +
+		months[localDate.getUTCMonth()] + ' ' +
+		localDate.getUTCFullYear();
+	var localTimeStr = // e.g. '21:49:46'
+		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
+		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
+		padLeft(localDate.getUTCSeconds(), 2, '0');
+
+	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
+}
+
+/* end of datetime.js */

gitweb/Makefile, gitweb/static/js/lib/cookies.js

diff --git a/gitweb/Makefile b/gitweb/Makefile
index 403265a..7dd1dee 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -118,6 +118,7 @@ GITWEB_FILES += static/git-logo.png static/git-favicon.png
 # then the rest of files; js/gitweb.js should be last (if it exists)
 GITWEB_JSLIB_FILES += static/js/lib/common-lib.js
 GITWEB_JSLIB_FILES += static/js/lib/datetime.js
+GITWEB_JSLIB_FILES += static/js/lib/cookies.js
 GITWEB_JSLIB_FILES += static/js/javascript-detection.js
 GITWEB_JSLIB_FILES += static/js/blame_incremental.js
 
diff --git a/gitweb/static/js/lib/cookies.js b/gitweb/static/js/lib/cookies.js
new file mode 100644
index 0000000..72b51cd
--- /dev/null
+++ b/gitweb/static/js/lib/cookies.js
@@ -0,0 +1,114 @@
+/**
+ * @fileOverview Accessing cookies from JavaScript
+ * @license GPLv2 or later
+ */
+
+/*
+ * Based on subsection "Cookies in JavaScript" of "Professional
+ * JavaScript for Web Developers" by Nicholas C. Zakas and cookie
+ * plugin from jQuery (dual licensed under the MIT and GPL licenses)
+ */
+
+
+/**
+ * Create a cookie with the given name and value,
+ * and other optional parameters.
+ *
+ * @example
+ *   setCookie('foo', 'bar'); // will be deleted when browser exits
+ *   setCookie('foo', 'bar', { expires: new Date(Date.parse('Jan 1, 2012')) });
+ *   setCookie('foo', 'bar', { expires: 7 }); // 7 days = 1 week
+ *   setCookie('foo', 'bar', { expires: 14, path: '/' });
+ *
+ * @param {String} sName:    Unique name of a cookie (letters, numbers, underscores).
+ * @param {String} sValue:   The string value stored in a cookie.
+ * @param {Object} [options] An object literal containing key/value pairs
+ *                           to provide optional cookie attributes.
+ * @param {String|Number|Date} [options.expires] Either literal string to be used as cookie expires,
+ *                            or an integer specifying the expiration date from now on in days,
+ *                            or a Date object to be used as cookie expiration date.
+ *                            If a negative value is specified or a date in the past),
+ *                            the cookie will be deleted.
+ *                            If set to null or omitted, the cookie will be a session cookie
+ *                            and will not be retained when the the browser exits.
+ * @param {String} [options.path] Restrict access of a cookie to particular directory
+ *                               (default: path of page that created the cookie).
+ * @param {String} [options.domain] Override what web sites are allowed to access cookie
+ *                                  (default: domain of page that created the cookie).
+ * @param {Boolean} [options.secure] If true, the secure attribute of the cookie will be set
+ *                                   and the cookie would be accessible only from secure sites
+ *                                   (cookie transmission will require secure protocol like HTTPS).
+ */
+function setCookie(sName, sValue, options) {
+	options = options || {};
+	if (sValue === null) {
+		sValue = '';
+		option.expires = 'delete';
+	}
+
+	var sCookie = sName + '=' + encodeURIComponent(sValue);
+
+	if (options.expires) {
+		var oExpires = options.expires, sDate;
+		if (oExpires === 'delete') {
+			sDate = 'Thu, 01 Jan 1970 00:00:00 GMT';
+		} else if (typeof oExpires === 'string') {
+			sDate = oExpires;
+		} else {
+			var oDate;
+			if (typeof oExpires === 'number') {
+				oDate = new Date();
+				oDate.setTime(oDate.getTime() + (oExpires * 24 * 60 * 60 * 1000)); // days to ms
+			} else {
+				oDate = oExpires;
+			}
+			sDate = oDate.toGMTString();
+		}
+		sCookie += '; expires=' + sDate;
+	}
+
+	if (options.path) {
+		sCookie += '; path=' + (options.path);
+	}
+	if (options.domain) {
+		sCookie += '; domain=' + (options.domain);
+	}
+	if (options.secure) {
+		sCookie += '; secure';
+	}
+	document.cookie = sCookie;
+}
+
+/**
+ * Get the value of a cookie with the given name.
+ *
+ * @param {String} sName: Unique name of a cookie (letters, numbers, underscores)
+ * @returns {String|null} The string value stored in a cookie
+ */
+function getCookie(sName) {
+	var sRE = '(?:; )?' + sName + '=([^;]*);?';
+	var oRE = new RegExp(sRE);
+	if (oRE.test(document.cookie)) {
+		return decodeURIComponent(RegExp['$1']);
+	} else {
+		return null;
+	}
+}
+
+/**
+ * Delete cookie with given name
+ *
+ * @param {String} sName:    Unique name of a cookie (letters, numbers, underscores)
+ * @param {Object} [options] An object literal containing key/value pairs
+ *                           to provide optional cookie attributes.
+ * @param {String} [options.path]   Must be the same as when setting a cookie
+ * @param {String} [options.domain] Must be the same as when setting a cookie
+ */
+function deleteCookie(sName, options) {
+	options = options || {};
+	options.expires = 'delete';
+
+	setCookie(sName, '', options);
+}
+
+/* end of cookies.js */

diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index d6b0c0d..b371391 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -89,6 +89,57 @@ function createRequestObject() {
 
 
 /* ............................................................ */
+/* Support for legacy browsers */
+
+/**
+ * Provides getElementsByClassName method, if there is no native
+ * implementation of this method.
+ *
+ * NOTE that there are limits and differences compared to native
+ * getElementsByClassName as defined by e.g.:
+ *   https://developer.mozilla.org/en/DOM/document.getElementsByClassName
+ *   http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#dom-getelementsbyclassname
+ *   http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#dom-document-getelementsbyclassname
+ *
+ * Namely, this implementation supports only single class name as
+ * argument and not set of space-separated tokens representing classes,
+ * it returns Array of nodes rather than live NodeList, and has
+ * additional optional argument where you can limit search to given tags
+ * (via getElementsByTagName).
+ *
+ * Based on
+ *   http://code.google.com/p/getelementsbyclassname/
+ *   http://www.dustindiaz.com/getelementsbyclass/
+ *   http://stackoverflow.com/questions/1818865/do-we-have-getelementsbyclassname-in-javascript
+ *
+ * See also http://ejohn.org/blog/getelementsbyclassname-speed-comparison/
+ *
+ * @param {String} class: name of _single_ class to find
+ * @param {String} [taghint] limit search to given tags
+ * @returns {Node[]} array of matching elements
+ */
+if (!('getElementsByClassName' in document)) {
+	document.getElementsByClassName = function (classname, taghint) {
+		taghint = taghint || "*";
+		var elements = (taghint === "*" && document.all) ?
+		               document.all :
+		               document.getElementsByTagName(taghint);
+		var pattern = new RegExp("(^|\\s)" + classname + "(\\s|$)");
+		var matches= [];
+		for (var i = 0, j = 0, n = elements.length; i < n; i++) {
+			var el= elements[i];
+			if (el.className && pattern.test(el.className)) {
+				// matches.push(el);
+				matches[j] = el;
+				j++;
+			}
+		}
+		return matches;
+	};
+} // end if
+
+
+/* ............................................................ */
 /* unquoting/unescaping filenames */
 
 /**#@+

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index ee69ea6..7329db2 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3938,22 +3938,21 @@ sub git_print_section {
 	print $cgi->end_div;
 }
 
-sub print_local_time {
-	print format_local_time(@_);
-}
+sub format_timestamp_html {
+	my ($date, %opts) = @_;
+	my $strtime = $date->{'rfc2822'};
 
-sub format_local_time {
-	my $localtime = '';
-	my %date = @_;
-	if ($date{'hour_local'} < 6) {
-		$localtime .= sprintf(" (<span class=\"atnight\">%02d:%02d</span> %s)",
-			$date{'hour_local'}, $date{'minute_local'}, $date{'tz_local'});
-	} else {
-		$localtime .= sprintf(" (%02d:%02d %s)",
-			$date{'hour_local'}, $date{'minute_local'}, $date{'tz_local'});
+	return $strtime unless $opts{'-localtime'};
+
+	my $localtime_format = '(%02d:%02d %s)';
+	if ($date->{'hour_local'} < 6) {
+		$localtime_format = '(<span class="atnight">%02d:%02d</span> %s)';
 	}
+	$strtime .= ' ' .
+	            sprintf($localtime_format,
+	                    $date->{'hour_local'}, $date->{'minute_local'}, $date->{'tz_local'});
 
-	return $localtime;
+	return $strtime;
 }
 
 # Outputs the author name and date in long form
@@ -3966,10 +3965,9 @@ sub git_print_authorship {
 	my %ad = parse_date($co->{'author_epoch'}, $co->{'author_tz'});
 	print "<$tag class=\"author_date\">" .
 	      format_search_author($author, "author", esc_html($author)) .
-	      " [$ad{'rfc2822'}";
-	print_local_time(%ad) if ($opts{-localtime});
-	print "]" . git_get_avatar($co->{'author_email'}, -pad_before => 1)
-		  . "</$tag>\n";
+	      " [".format_timestamp_html(\%ad, %opts)."]".
+	      git_get_avatar($co->{'author_email'}, -pad_before => 1) .
+	      "</$tag>\n";
 }
 
 # Outputs table rows containing the full author or committer information,
@@ -3986,16 +3984,16 @@ sub git_print_authorship_rows {
 		my %wd = parse_date($co->{"${who}_epoch"}, $co->{"${who}_tz"});
 		print "<tr><td>$who</td><td>" .
 		      format_search_author($co->{"${who}_name"}, $who,
-			       esc_html($co->{"${who}_name"})) . " " .
+		                           esc_html($co->{"${who}_name"})) . " " .
 		      format_search_author($co->{"${who}_email"}, $who,
-			       esc_html("<" . $co->{"${who}_email"} . ">")) .
+		                           esc_html("<" . $co->{"${who}_email"} . ">")) .
 		      "</td><td rowspan=\"2\">" .
 		      git_get_avatar($co->{"${who}_email"}, -size => 'double') .
 		      "</td></tr>\n" .
 		      "<tr>" .
-		      "<td></td><td> $wd{'rfc2822'}";
-		print_local_time(%wd);
-		print "</td>" .
+		      "<td></td><td>" .
+		      format_timestamp_html(\%wd, -localtime=>1) .
+		      "</td>" .
 		      "</tr>\n";
 	}
 }
@@ -5410,7 +5408,8 @@ sub git_summary {
 	      "<tr id=\"metadata_desc\"><td>description</td><td>" . esc_html($descr) . "</td></tr>\n" .
 	      "<tr id=\"metadata_owner\"><td>owner</td><td>" . esc_html($owner) . "</td></tr>\n";
 	if (defined $cd{'rfc2822'}) {
-		print "<tr id=\"metadata_lchange\"><td>last change</td><td>$cd{'rfc2822'}</td></tr>\n";
+		print "<tr id=\"metadata_lchange\"><td>last change</td>" .
+		      "<td>".format_timestamp_html(\%cd)."</td></tr>\n";
 	}
 
 	# use per project git URL list in $projectroot/$project/cloneurl

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 7329db2..67bcfe8 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3939,11 +3939,9 @@ sub git_print_section {
 }
 
 sub format_timestamp_html {
-	my ($date, %opts) = @_;
+	my $date = shift;
 	my $strtime = $date->{'rfc2822'};
 
-	return $strtime unless $opts{'-localtime'};
-
 	my $localtime_format = '(%02d:%02d %s)';
 	if ($date->{'hour_local'} < 6) {
 		$localtime_format = '(<span class="atnight">%02d:%02d</span> %s)';
@@ -3965,7 +3963,7 @@ sub git_print_authorship {
 	my %ad = parse_date($co->{'author_epoch'}, $co->{'author_tz'});
 	print "<$tag class=\"author_date\">" .
 	      format_search_author($author, "author", esc_html($author)) .
-	      " [".format_timestamp_html(\%ad, %opts)."]".
+	      " [".format_timestamp_html(\%ad)."]".
 	      git_get_avatar($co->{'author_email'}, -pad_before => 1) .
 	      "</$tag>\n";
 }
@@ -3992,7 +3990,7 @@ sub git_print_authorship_rows {
 		      "</td></tr>\n" .
 		      "<tr>" .
 		      "<td></td><td>" .
-		      format_timestamp_html(\%wd, -localtime=>1) .
+		      format_timestamp_html(\%wd) .
 		      "</td>" .
 		      "</tr>\n";
 	}

gitweb/Makefile, gitweb/gitweb.perl, gitweb/static/js/adjust-timezone.js, gitweb/static/js/lib/datetime.js

diff --git a/gitweb/Makefile b/gitweb/Makefile
index 7dd1dee..5d20515 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -120,6 +120,7 @@ GITWEB_JSLIB_FILES += static/js/lib/common-lib.js
 GITWEB_JSLIB_FILES += static/js/lib/datetime.js
 GITWEB_JSLIB_FILES += static/js/lib/cookies.js
 GITWEB_JSLIB_FILES += static/js/javascript-detection.js
+GITWEB_JSLIB_FILES += static/js/adjust-timezone.js
 GITWEB_JSLIB_FILES += static/js/blame_incremental.js
 
 
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 67bcfe8..6651946 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3732,9 +3732,14 @@ sub git_footer_html {
 		      qq!startBlame("!. href(action=>"blame_data", -replay=>1) .qq!",\n!.
 		      qq!           "!. href() .qq!");\n!.
 		      qq!</script>\n!;
-	} elsif (gitweb_check_feature('javascript-actions')) {
+	} else {
 		print qq!<script type="text/javascript">\n!.
-		      qq!window.onload = fixLinks;\n!.
+		      qq!window.onload = function () {\n!.
+		      (gitweb_check_feature('javascript-actions') ?
+		      qq!	fixLinks();\n! : '').
+		      # last parameter to onloadTZSetup must be CSS class used by format_timestamp_html
+		      qq!	onloadTZSetup('local', 'gitweb_tz', 'datetime');\n!.
+		      qq!};\n!.
 		      qq!</script>\n!;
 	}
 
@@ -3940,7 +3945,7 @@ sub git_print_section {
 
 sub format_timestamp_html {
 	my $date = shift;
-	my $strtime = $date->{'rfc2822'};
+	my $strtime = '<span class="datetime">'.$date->{'rfc2822'}.'</span>';
 
 	my $localtime_format = '(%02d:%02d %s)';
 	if ($date->{'hour_local'} < 6) {
diff --git a/gitweb/static/js/adjust-timezone.js b/gitweb/static/js/adjust-timezone.js
new file mode 100644
index 0000000..5cebc08
--- /dev/null
+++ b/gitweb/static/js/adjust-timezone.js
@@ -0,0 +1,59 @@
+// Copyright (C) 2011, John 'Warthog9' Hawley <warthog9@eaglescrag.net>
+//               2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview Manipulate dates in gitweb output, adjusting timezone
+ * @license GPLv2 or later
+ */
+
+/**
+ * Get common timezone and adjust dates to use this common timezone.
+ *
+ * This function is called during onload event (added to window.onload).
+ *
+ * @param {String} tzDefault: default timezone, if there is no cookie
+ * @param {String} tzCookieName: name of cookie to store timezone
+ * @param {String} tzClassName: denotes elements with date to be adjusted
+ */
+function onloadTZSetup(tzDefault, tzCookieName, tzClassName) {
+	var tzCookie = getCookie(tzCookieName);
+	var tz = tzCookie ? tzCookie : tzDefault;
+
+	// server-side of gitweb produces datetime in UTC,
+	// so if tz is 'utc' there is no need for changes
+	if (tz !== 'utc') {
+		fixDatetimeTZ(tz, tzClassName);
+	}
+}
+
+
+/**
+ * Replace RFC-2822 dates contained in SPAN elements with tzClassName
+ * CSS class with equivalent dates in given timezone.
+ *
+ * @param {String} tz: numeric timezone in '(-|+)HHMM' format, or 'utf', or 'local'
+ * @param {String} tzClassName: specifies elements to be changed
+ */
+function fixDatetimeTZ(tz, tzClassName) {
+	// sanity check, method should be ensured by common-lib.js
+	if (!document.getElementsByClassName) {
+		return;
+	}
+
+	// translate to timezone in '(-|+)HHMM' format
+	tz = normalizeTimezoneInfo(tz);
+
+	// NOTE: result of getElementsByClassName should probably be cached
+	var classesFound = document.getElementsByClassName(tzClassName, "span");
+	for (var i = 0, len = classesFound.length; i < len; i++) {
+		var curElement = classesFound[i];
+
+		var epoch = parseRFC2822Date(curElement.innerHTML);
+		var adjusted = formatDateRFC2882(epoch, tz);
+
+		// curElement.innerHTML = adjusted; // does not work for Mozilla 1.17.2
+		curElement.firstChild.data = adjusted;
+	}
+}
+
+/* end of adjust-timezone.js */
diff --git a/gitweb/static/js/lib/datetime.js b/gitweb/static/js/lib/datetime.js
index b3dcedb..f78c60a 100644
--- a/gitweb/static/js/lib/datetime.js
+++ b/gitweb/static/js/lib/datetime.js
@@ -105,6 +105,21 @@ function formatTimezoneInfo(hours, minutes, sep) {
 }
 
 /**
+ * translate 'utc' and 'local' to numerical timezone
+ * @param {String} timezoneInfo: might be 'utc' or 'local' (browser)
+ */
+function normalizeTimezoneInfo(timezoneInfo) {
+	switch (timezoneInfo) {
+	case 'utc':
+		return '+0000';
+	case 'local': // 'local' is browser timezone
+		return localTimezoneInfo();
+	}
+	return timezoneInfo;
+}
+
+
+/**
  * return date in local time formatted in iso-8601 like format
  * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
  *

gitweb/static/gitweb.css, gitweb/static/js/adjust-timezone.js, gitweb/static/js/lib/common-lib.js

diff --git a/gitweb/static/gitweb.css b/gitweb/static/gitweb.css
index 79d7eeb..6d17e12 100644
--- a/gitweb/static/gitweb.css
+++ b/gitweb/static/gitweb.css
@@ -579,6 +579,31 @@ div.remote {
 	display: inline-block;
 }
 
+/* JavaScript-base timezone manipulation */
+
+.popup { // timezone selection UI
+	position: absolute;
+	top: 0; right: 0;
+	border: 1px solid;
+	background-color: #f0f0f0;
+}
+
+.close-button { // close timezone selection UI without selecting
+	//float: right; // float doesn't work within absolutely positioned container
+	position: absolute;
+	top: 0px; right: 0px;
+	border:  1px solid green;
+	margin:  1px 1px 1px 1px;
+	padding: 1px 1px 1px 1px;
+	width:     10px;
+	height:    10px;
+	font-size:  8px;
+	font-weight: bold;
+	text-align: center;
+	background-color: #fff0f0;
+}
+
+
 /* Style definition generated by highlight 2.4.5, http://www.andre-simon.de/ */
 
 /* Highlighting theme definition: */
diff --git a/gitweb/static/js/adjust-timezone.js b/gitweb/static/js/adjust-timezone.js
index 5cebc08..6ac32ca 100644
--- a/gitweb/static/js/adjust-timezone.js
+++ b/gitweb/static/js/adjust-timezone.js
@@ -7,7 +7,8 @@
  */
 
 /**
- * Get common timezone and adjust dates to use this common timezone.
+ * Get common timezone, add UI for changing timezones, and adjust
+ * dates to use requested common timezone.
  *
  * This function is called during onload event (added to window.onload).
  *
@@ -17,13 +18,20 @@
  */
 function onloadTZSetup(tzDefault, tzCookieName, tzClassName) {
 	var tzCookie = getCookie(tzCookieName);
-	var tz = tzCookie ? tzCookie : tzDefault;
+	var tz = tzDefault;
 
-	// server-side of gitweb produces datetime in UTC,
-	// so if tz is 'utc' there is no need for changes
-	if (tz !== 'utc') {
-		fixDatetimeTZ(tz, tzClassName);
+	if (tzCookie) {
+		// set timezone to value saved in a cookie
+		tz = tzCookie;
+		// refresh cookie, so it expires 7 days from last use of gitweb
+		setCookie(tzCookieName, tzCookie, { expires: 7, path: '/' });
 	}
+
+	// add UI for changing timezone
+	addChangeTZ(tz, tzCookieName, tzClassName);
+
+	// adjust dates to use specified common timezone
+	fixDatetimeTZ(tz, tzClassName);
 }
 
 
@@ -40,6 +48,10 @@ function fixDatetimeTZ(tz, tzClassName) {
 		return;
 	}
 
+	// server-side of gitweb produces datetime in UTC,
+	// so if tz is 'utc' there is no need for changes
+	var nochange = tz === 'utc';
+
 	// translate to timezone in '(-|+)HHMM' format
 	tz = normalizeTimezoneInfo(tz);
 
@@ -48,12 +60,222 @@ function fixDatetimeTZ(tz, tzClassName) {
 	for (var i = 0, len = classesFound.length; i < len; i++) {
 		var curElement = classesFound[i];
 
-		var epoch = parseRFC2822Date(curElement.innerHTML);
-		var adjusted = formatDateRFC2882(epoch, tz);
+		curElement.title = 'Click to change timezone';
+		if (!nochange) {
+			var epoch = parseRFC2822Date(curElement.innerHTML);
+			var adjusted = formatDateRFC2882(epoch, tz);
+
+			// curElement.innerHTML = adjusted; // does not work for Mozilla 1.17.2
+			curElement.firstChild.data = adjusted;
+		}
+	}
+}
+
+/**
+ * Adds triggers for UI to change common timezone used for dates in
+ * gitweb output: it marks up and/or creates item to click to invoke
+ * timezone change UI, creates timezone UI fragment to be attached,
+ * and instals appropriate onclick trigger (via event delegation).
+ *
+ * @param {String} tzSelected: pre-selected timezone,
+ *                             'utf' or 'local' or '(-|+)HHMM'
+ * @param {String} tzCookieName: name of cookie to store selection
+ * @param {String} tzClassName: specifies elements to install trigger
+ */
+function addChangeTZ(tzSelected, tzCookieName, tzClassName) {
+	// make link to timezone UI discoverable
+	addCssRule('.'+tzClassName + ':hover',
+	           'text-decoration: underline; cursor: help;');
+
+	// create form for selecting timezone (to be saved in a cookie)
+	var tzSelectFragment = document.createDocumentFragment();
+	tzSelectFragment = createChangeTZForm(tzSelectFragment,
+	                                      tzSelected, tzCookieName, tzClassName);
+
+	// event delegation handler for timezone selection UI (clicking on entry)
+	// see http://www.nczonline.net/blog/2009/06/30/event-delegation-in-javascript/
+	// assumes that there is no existing document.onclick handler
+	document.onclick = function onclickHandler(event) {
+		//IE doesn't pass in the event object
+		event = event || window.event;
+
+		//IE uses srcElement as the target
+		var target = event.target || event.srcElement;
+
+		switch (target.className) {
+		case tzClassName:
+			displayChangeTZForm(target, tzSelectFragment);
+			break;
+		} // end switch
+	};
+}
+
+/**
+ * Create DocumentFragment with UI for changing common timezone in
+ * which dates are shown in.
+ *
+ * @param {DocumentFragment} documentFragment: where attach UI
+ * @param {String} tzSelected: default (pre-selected) timezone
+ * @param {String} tzCookieName: name of cookie to save result of selection
+ * @returns {DocumentFragment}
+ */
+function createChangeTZForm(documentFragment, tzSelected, tzCookieName, tzClassName) {
+	var div = document.createElement("div");
+	div.className = 'popup';
+	///*
+	div.style.cssText =
+		'position: absolute; top: 0; right: 0; ' +
+		'border: 1pt solid; background-color: #f0f0f0;';
+	//*/
+
+	var closeButton = document.createElement('div');
+	closeButton.className = 'close-button';
+	///*
+	closeButton.style.cssText =
+		//'float: right; '+ // float doesn't work within absolutely positioned container
+		'position: absolute; top: 0px; right: 0px; '+
+		'border: 1px solid green; margin: 1px 1px 1px 1px; '+
+		'background-color: #fff0f0; font-weight: bold; font-size: 8px; text-align: center; ' +
+		'width: 10px; height: 10px; padding: 1px 1px 1px 1px;';
+	//*/
+	closeButton.title = '(click on this box to close)';
+	closeButton.appendChild(document.createTextNode('X'));
+	closeButton.onclick = function onclickCloseTZForm(event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		removeChangeTZForm(documentFragment, target, tzClassName);
+	};
+	div.appendChild(closeButton);
+
+	div.appendChild(document.createTextNode('Select timezone: '));
+	var br = document.createElement('br');
+	br.clear = 'all';
+	div.appendChild(br);
+
+	var select = document.createElement("select");
+	select.name = "tzoffset";
+	//select.style.clear = 'all';
+
+	var timezones = generateTZList();
+	for (var i = 0, len = timezones.length; i < len; i++) {
+		var tzone = timezones[i];
+		var option = document.createElement("option");
+		if (tzone.value === tzSelected) {
+			option.defaultSelected = true;
+		}
+		option.value = tzone.value;
+		option.appendChild(document.createTextNode(tzone.descr));
+
+		select.appendChild(option);
+	}
+
+	select.onchange = function onTZFormChange(event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
 
-		// curElement.innerHTML = adjusted; // does not work for Mozilla 1.17.2
-		curElement.firstChild.data = adjusted;
+		removeChangeTZForm(documentFragment, target, tzClassName);
+
+		var selected = target.options.item(target.selectedIndex);
+		if (selected) {
+			selected.defaultSelected = true;
+			setCookie(tzCookieName, selected.value, { expires: 7, path: '/' });
+			fixDatetimeTZ(selected.value, tzClassName);
+		}
+	};
+	// NOTE: onblur removal might be not necessary with close button
+	// NOTE: the same function (closure) as for closeButton.onclick
+	select.onblur = function onTZFormBlur(event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		removeChangeTZForm(documentFragment, target, tzClassName);
+	};
+
+	div.appendChild(select);
+	documentFragment.appendChild(div);
+
+	return documentFragment;
+}
+
+
+/**
+ * Hide (remove from DOM) timezone change UI, ensuring that it is not
+ * garbage collected and that it can be re-enabled later.
+ *
+ * @param {DocumentFragment} documentFragment: contains detached UI
+ * @param {HTMLSelectElement} target: select element inside of UI
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {DocumentFragment} documentFragment
+ */
+function removeChangeTZForm(documentFragment, target, tzClassName) {
+	// find containing element, where we appended timezone selection UI
+	var container = target.parentNode;
+	while (container &&
+	       container.className !== tzClassName) {
+		container = container.parentNode;
+	}
+	// safety check if we found correct container,
+	// and if it isn't deleted already
+	if (!container ||
+	    container.className !== tzClassName ||
+	    container.lastChild.className !== 'popup') {
+		return documentFragment;
+	}
+
+	// timezone selection UI was appended as last child
+	// see also displayChangeTZForm function
+	var removed = container.removeChild(container.lastChild);
+	if (documentFragment.firstChild !== removed) {
+		// re-append it so it would be available for next time
+		documentFragment.appendChild(removed);
+	}
+	container.style.removeProperty('position');
+	if (!container.style.cssText) {
+		container.removeAttribute('style');
 	}
+
+	return documentFragment;
+}
+
+
+/**
+ * Display UI for changing common timezone for dates in gitweb output.
+ * To be used from 'onclick' event handler.
+ *
+ * @param {HTMLElement} target: where to install/display UI
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ */
+function displayChangeTZForm(target, tzSelectFragment) {
+	// for absolute positioning to be related to target element
+	target.style.position = 'relative';
+
+	// show/display UI for changing timezone
+	target.appendChild(tzSelectFragment);
+}
+
+
+/**
+ * Generate list of timezones for creating timezone select UI
+ *
+ * @returns {Object[]} list of e.g. { value: '+0100', descr: 'GMT+01:00' }
+ */
+function generateTZList() {
+	var timezones = [
+		{ value: "utc",   descr: "UTC/GMT"},
+		{ value: "local", descr: "Local (per browser)"}
+	];
+
+	// generate all full hour timezones (no fractional timezones)
+	for (var x = -12, idx = timezones.length; x <= +14; x++, idx++) {
+		var hours = (x >= 0 ? '+' : '-') + padLeft(x >=0 ? x : -x, 2);
+		timezones[idx] = { value: hours + '00', descr: 'UTC' + hours + ':00'};
+		if (x === 0) {
+			timezones[idx].descr = 'UTC\u00B100:00'; // 'UTC&plusmn;00:00'
+		}
+	}
+
+	return timezones;
 }
 
 /* end of adjust-timezone.js */
diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index b371391..faff9b6 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -64,7 +64,7 @@ function padLeft(input, width, ch) {
 
 
 /* ............................................................ */
-/* Ajax */
+/* Handling browser incompatibilities */
 
 /**
  * Create XMLHttpRequest object in cross-browser way
@@ -88,6 +88,31 @@ function createRequestObject() {
 }
 
 
+/**
+ * Insert rule giving specified STYLE to given SELECTOR at the end of
+ * first CSS stylesheet.
+ *
+ * @param {String} selector: CSS selector, e.g. '.class'
+ * @param {String} style: rule contents, e.g. 'background-color: red;'
+ */
+function addCssRule(selector, style) {
+	var stylesheet = document.styleSheets[0];
+
+	var theRules = [];
+	if (stylesheet.cssRules) {     // W3C way
+		theRules = stylesheet.cssRules;
+	} else if (stylesheet.rules) { // IE way
+		theRules = stylesheet.rules;
+	}
+
+	if (stylesheet.insertRule) {    // W3C way
+		stylesheet.insertRule(selector + ' { ' + style + ' }', theRules.length);
+	} else if (stylesheet.addRule) { // IE way
+		stylesheets.addRule(selector, style);
+	}
+}
+
+
 /* ............................................................ */
 /* Support for legacy browsers */
 

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 6651946..b80f2e0 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -480,6 +480,18 @@ our %feature = (
 		'override' => 0,
 		'default' => [0]},
 
+	# Enable and configure ability to change common timezone for dates
+	# in gitweb output via JavaScript.  Enabled by default.
+	# Project specific override is not supported.
+	'javascript-timezone' => {
+		'override' => 0,
+		'default' => [
+			'local',     # default timezone: 'utc', 'local', or '(-|+)HHMM' format,
+			             # or undef to turn off this feature
+			'gitweb_tz', # name of cookie where to store selected timezone
+			'datetime',  # CSS class used to mark up dates for manipulation
+		]},
+
 	# Syntax highlighting support. This is based on Daniel Svensson's
 	# and Sham Chukoury's work in gitweb-xmms2.git.
 	# It requires the 'highlight' program present in $PATH,
@@ -3733,13 +3745,18 @@ sub git_footer_html {
 		      qq!           "!. href() .qq!");\n!.
 		      qq!</script>\n!;
 	} else {
+		my ($jstimezone, $tz_cookie, $datetime_class) =
+			gitweb_get_feature('javascript-timezone');
+
 		print qq!<script type="text/javascript">\n!.
-		      qq!window.onload = function () {\n!.
-		      (gitweb_check_feature('javascript-actions') ?
-		      qq!	fixLinks();\n! : '').
-		      # last parameter to onloadTZSetup must be CSS class used by format_timestamp_html
-		      qq!	onloadTZSetup('local', 'gitweb_tz', 'datetime');\n!.
-		      qq!};\n!.
+		      qq!window.onload = function () {\n!;
+		if (gitweb_check_feature('javascript-actions')) {
+			print qq!	fixLinks();\n!;
+		}
+		if ($jstimezone && $tz_cookie && $datetime_class) {
+			print qq!	onloadTZSetup('$jstimezone', '$tz_cookie', '$datetime_class');\n!;
+		}
+		print qq!};\n!.
 		      qq!</script>\n!;
 	}
 
@@ -3945,7 +3962,13 @@ sub git_print_section {
 
 sub format_timestamp_html {
 	my $date = shift;
-	my $strtime = '<span class="datetime">'.$date->{'rfc2822'}.'</span>';
+	my $strtime = $date->{'rfc2822'};
+
+	my (undef, undef, $datetime_class) =
+		gitweb_get_feature('javascript-timezone');
+	if ($datetime_class) {
+		$strtime = qq!<span class="datetime">$strtime</span>!;
+	}
 
 	my $localtime_format = '(%02d:%02d %s)';
 	if ($date->{'hour_local'} < 6) {

gitweb/gitweb.perl, gitweb/static/gitweb.css, gitweb/static/js/adjust-timezone.js, gitweb/static/js/lib/common-lib.js

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 6651946..b1e80ef 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3738,7 +3738,8 @@ sub git_footer_html {
 		      (gitweb_check_feature('javascript-actions') ?
 		      qq!	fixLinks();\n! : '').
 		      # last parameter to onloadTZSetup must be CSS class used by format_timestamp_html
-		      qq!	onloadTZSetup('local', 'gitweb_tz', 'datetime');\n!.
+		      qq!	var tz_cookie = { name: 'gitweb_tz', expires: 14, path: '/' };\n!. # in days
+		      qq!	onloadTZSetup('local', tz_cookie, 'datetime');\n!.
 		      qq!};\n!.
 		      qq!</script>\n!;
 	}
diff --git a/gitweb/static/gitweb.css b/gitweb/static/gitweb.css
index 79d7eeb..8dd0935 100644
--- a/gitweb/static/gitweb.css
+++ b/gitweb/static/gitweb.css
@@ -579,6 +579,39 @@ div.remote {
 	display: inline-block;
 }
 
+/* JavaScript-based timezone manipulation */
+
+.popup { /* timezone selection UI */
+	position: absolute;
+	/* "top: 0; right: 0;" would be better, if not for bugs in browsers */
+	top: 0; left: 0;
+	border: 1px solid;
+	padding: 2px;
+	background-color: #f0f0f0;
+	font-style: normal;
+	color: #000000;
+	cursor: auto;
+}
+
+.close-button { /* close timezone selection UI without selecting */
+	/* float doesn't work within absolutely positioned container,
+	 * if width of container is not set explicitly */
+	/* float: right; */
+	position: absolute;
+	top: 0px; right: 0px;
+	border:  1px solid green;
+	margin:  1px 1px 1px 1px;
+	padding-bottom: 2px;
+	width:     12px;
+	height:    10px;
+	font-size:  9px;
+	font-weight: bold;
+	text-align: center;
+	background-color: #fff0f0;
+	cursor: pointer;
+}
+
+
 /* Style definition generated by highlight 2.4.5, http://www.andre-simon.de/ */
 
 /* Highlighting theme definition: */
diff --git a/gitweb/static/js/adjust-timezone.js b/gitweb/static/js/adjust-timezone.js
index c9b69c3..f1e97a6 100644
--- a/gitweb/static/js/adjust-timezone.js
+++ b/gitweb/static/js/adjust-timezone.js
@@ -7,34 +7,51 @@
  */
 
 /**
- * Get common timezone and adjust dates to use this common timezone.
+ * Get common timezone, add UI for changing timezones, and adjust
+ * dates to use requested common timezone.
  *
  * This function is called during onload event (added to window.onload).
  *
  * @param {String} tzDefault: default timezone, if there is no cookie
- * @param {String} tzCookieName: name of cookie to store timezone
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzCookieInfo.name: name of cookie to store timezone
  * @param {String} tzClassName: denotes elements with date to be adjusted
  */
-function onloadTZSetup(tzDefault, tzCookieName, tzClassName) {
-	var tzCookie = getCookie(tzCookieName);
-	var tz = tzCookie ? tzCookie : tzDefault;
+function onloadTZSetup(tzDefault, tzCookieInfo, tzClassName) {
+	var tzCookieTZ = getCookie(tzCookieInfo.name, tzCookieInfo);
+	var tz = tzDefault;
+
+	if (tzCookieTZ) {
+		// set timezone to value saved in a cookie
+		tz = tzCookieTZ;
+		// refresh cookie, so its expiration counts from last use of gitweb
+		setCookie(tzCookieInfo.name, tzCookieTZ, tzCookieInfo);
+	}
+
+	// add UI for changing timezone
+	addChangeTZ(tz, tzCookieInfo, tzClassName);
 
 	// server-side of gitweb produces datetime in UTC,
 	// so if tz is 'utc' there is no need for changes
-	if (tz !== 'utc') {
-		fixDatetimeTZ(tz, tzClassName);
-	}
+	var nochange = tz === 'utc';
+
+	// adjust dates to use specified common timezone
+	fixDatetimeTZ(tz, tzClassName, nochange);
 }
 
 
+/* ...................................................................... */
+/* Changing dates to use requested timezone */
+
 /**
  * Replace RFC-2822 dates contained in SPAN elements with tzClassName
  * CSS class with equivalent dates in given timezone.
  *
  * @param {String} tz: numeric timezone in '(-|+)HHMM' format, or 'utc', or 'local'
  * @param {String} tzClassName: specifies elements to be changed
+ * @param {Boolean} nochange: markup for timezone change, but don't change it
  */
-function fixDatetimeTZ(tz, tzClassName) {
+function fixDatetimeTZ(tz, tzClassName, nochange) {
 	// sanity check, method should be ensured by common-lib.js
 	if (!document.getElementsByClassName) {
 		return;
@@ -48,12 +65,263 @@ function fixDatetimeTZ(tz, tzClassName) {
 	for (var i = 0, len = classesFound.length; i < len; i++) {
 		var curElement = classesFound[i];
 
-		var epoch = parseRFC2822Date(curElement.innerHTML);
-		var adjusted = formatDateRFC2882(epoch, tz);
+		curElement.title = 'Click to change timezone';
+		if (!nochange) {
+			var epoch = parseRFC2822Date(curElement.innerHTML);
+			var adjusted = formatDateRFC2882(epoch, tz);
+
+			// curElement.innerHTML = adjusted; // does not work for Mozilla 1.17.2
+			curElement.firstChild.data = adjusted;
+		}
+	}
+}
+
+
+/* ...................................................................... */
+/* Adding triggers, generating timezone menu, displaying and hiding */
+
+/**
+ * Adds triggers for UI to change common timezone used for dates in
+ * gitweb output: it marks up and/or creates item to click to invoke
+ * timezone change UI, creates timezone UI fragment to be attached,
+ * and installs appropriate onclick trigger (via event delegation).
+ *
+ * @param {String} tzSelected: pre-selected timezone,
+ *                             'utc' or 'local' or '(-|+)HHMM'
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzClassName: specifies elements to install trigger
+ */
+function addChangeTZ(tzSelected, tzCookieInfo, tzClassName) {
+	// make link to timezone UI discoverable
+	addCssRule('.'+tzClassName + ':hover',
+	           'text-decoration: underline; cursor: help;');
+
+	// create form for selecting timezone (to be saved in a cookie)
+	var tzSelectFragment = document.createDocumentFragment();
+	tzSelectFragment = createChangeTZForm(tzSelectFragment,
+	                                      tzSelected, tzCookieInfo, tzClassName);
+
+	// event delegation handler for timezone selection UI (clicking on entry)
+	// see http://www.nczonline.net/blog/2009/06/30/event-delegation-in-javascript/
+	// assumes that there is no existing document.onclick handler
+	document.onclick = function onclickHandler(event) {
+		//IE doesn't pass in the event object
+		event = event || window.event;
+
+		//IE uses srcElement as the target
+		var target = event.target || event.srcElement;
+
+		switch (target.className) {
+		case tzClassName:
+			displayChangeTZForm(target, tzSelectFragment);
+			break;
+		} // end switch
+	};
+}
+
+/**
+ * Create DocumentFragment with UI for changing common timezone in
+ * which dates are shown in.
+ *
+ * @param {DocumentFragment} documentFragment: where attach UI
+ * @param {String} tzSelected: default (pre-selected) timezone
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @returns {DocumentFragment}
+ */
+function createChangeTZForm(documentFragment, tzSelected, tzCookieInfo, tzClassName) {
+	var div = document.createElement("div");
+	div.className = 'popup';
+
+	/* '<div class="close-button" title="(click on this box to close)">X</div>' */
+	var closeButton = document.createElement('div');
+	closeButton.className = 'close-button';
+	closeButton.title = '(click on this box to close)';
+	closeButton.appendChild(document.createTextNode('X'));
+	closeButton.onclick = closeTZFormHandler(documentFragment, tzClassName);
+	div.appendChild(closeButton);
+
+	/* 'Select timezone: <br clear="all">' */
+	div.appendChild(document.createTextNode('Select timezone: '));
+	var br = document.createElement('br');
+	br.clear = 'all';
+	div.appendChild(br);
+
+	/* '<select name="tzoffset">
+	 *    ...
+	 *    <option value="-0700">UTC-07:00</option>
+	 *    <option value="-0600">UTC-06:00</option>
+	 *    ...
+	 *  </select>' */
+	var select = document.createElement("select");
+	select.name = "tzoffset";
+	//select.style.clear = 'all';
+	select.appendChild(generateTZOptions(tzSelected));
+	select.onchange = selectTZHandler(documentFragment, tzCookieInfo, tzClassName);
+	// NOTE: onblur removal might be not necessary with close button
+	select.onblur = closeTZFormHandler(documentFragment, tzClassName);
+	div.appendChild(select);
+
+	documentFragment.appendChild(div);
+
+	return documentFragment;
+}
+
+
+/**
+ * Hide (remove from DOM) timezone change UI, ensuring that it is not
+ * garbage collected and that it can be re-enabled later.
+ *
+ * @param {DocumentFragment} documentFragment: contains detached UI
+ * @param {HTMLSelectElement} target: select element inside of UI
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {DocumentFragment} documentFragment
+ */
+function removeChangeTZForm(documentFragment, target, tzClassName) {
+	// find containing element, where we appended timezone selection UI
+	// `target' is somewhere inside timezone menu
+	var container = target.parentNode, popup = target;
+	while (container &&
+	       container.className !== tzClassName) {
+		popup = container;
+		container = container.parentNode;
+	}
+	// safety check if we found correct container,
+	// and if it isn't deleted already
+	if (!container || !popup ||
+	    container.className !== tzClassName ||
+	    popup.className     !== 'popup') {
+		return documentFragment;
+	}
 
-		// curElement.innerHTML = adjusted; // does not work for Mozilla 1.17.2
-		curElement.firstChild.data = adjusted;
+	// timezone selection UI was appended as last child
+	// see also displayChangeTZForm function
+	var removed = container.removeChild(popup);
+	if (documentFragment.firstChild !== removed) { // the only child
+		// re-append it so it would be available for next time
+		documentFragment.appendChild(removed);
 	}
+	// all of inline style was added by this script
+	container.removeAttribute('style');
+
+	return documentFragment;
+}
+
+
+/**
+ * Display UI for changing common timezone for dates in gitweb output.
+ * To be used from 'onclick' event handler.
+ *
+ * @param {HTMLElement} target: where to install/display UI
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ */
+function displayChangeTZForm(target, tzSelectFragment) {
+	// for absolute positioning to be related to target element
+	target.style.position = 'relative';
+	target.style.display = 'inline-block';
+
+	// show/display UI for changing timezone
+	target.appendChild(tzSelectFragment);
+}
+
+
+/* ...................................................................... */
+/* List of timezones for timezone selection menu */
+
+/**
+ * Generate list of timezones for creating timezone select UI
+ *
+ * @returns {Object[]} list of e.g. { value: '+0100', descr: 'GMT+01:00' }
+ */
+function generateTZList() {
+	var timezones = [
+		{ value: "utc",   descr: "UTC/GMT"},
+		{ value: "local", descr: "Local (per browser)"}
+	];
+
+	// generate all full hour timezones (no fractional timezones)
+	for (var x = -12, idx = timezones.length; x <= +14; x++, idx++) {
+		var hours = (x >= 0 ? '+' : '-') + padLeft(x >=0 ? x : -x, 2);
+		timezones[idx] = { value: hours + '00', descr: 'UTC' + hours + ':00'};
+		if (x === 0) {
+			timezones[idx].descr = 'UTC\u00B100:00'; // 'UTC&plusmn;00:00'
+		}
+	}
+
+	return timezones;
+}
+
+/**
+ * Generate <options> elements for timezone select UI
+ *
+ * @param {String} tzSelected: default timezone
+ * @returns {DocumentFragment} list of options elements to appendChild
+ */
+function generateTZOptions(tzSelected) {
+	var elems = document.createDocumentFragment();
+	var timezones = generateTZList();
+
+	for (var i = 0, len = timezones.length; i < len; i++) {
+		var tzone = timezones[i];
+		var option = document.createElement("option");
+		if (tzone.value === tzSelected) {
+			option.defaultSelected = true;
+		}
+		option.value = tzone.value;
+		option.appendChild(document.createTextNode(tzone.descr));
+
+		elems.appendChild(option);
+	}
+
+	return elems;
+}
+
+
+/* ...................................................................... */
+/* Event handlers and/or their generators */
+
+/**
+ * Create event handler that select timezone and closes timezone select UI.
+ * To be used as $('select[name="tzselect"]').onchange handler.
+ *
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzCookieInfo.name: name of cookie to save result of selection
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {Function} event handler
+ */
+function selectTZHandler(tzSelectFragment, tzCookieInfo, tzClassName) {
+	//return function selectTZ(event) {
+	return function (event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		var selected = target.options.item(target.selectedIndex);
+		removeChangeTZForm(tzSelectFragment, target, tzClassName);
+
+		if (selected) {
+			selected.defaultSelected = true;
+			setCookie(tzCookieInfo.name, selected.value, tzCookieInfo);
+			fixDatetimeTZ(selected.value, tzClassName);
+		}
+	};
+}
+
+/**
+ * Create event handler that closes timezone select UI.
+ * To be used e.g. as $('.closebutton').onclick handler.
+ *
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {Function} event handler
+ */
+function closeTZFormHandler(tzSelectFragment, tzClassName) {
+	//return function closeTZForm(event) {
+	return function (event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		removeChangeTZForm(tzSelectFragment, target, tzClassName);
+	};
 }
 
 /* end of adjust-timezone.js */
diff --git a/gitweb/static/js/lib/common-lib.js b/gitweb/static/js/lib/common-lib.js
index b371391..018bbb7 100644
--- a/gitweb/static/js/lib/common-lib.js
+++ b/gitweb/static/js/lib/common-lib.js
@@ -64,7 +64,7 @@ function padLeft(input, width, ch) {
 
 
 /* ............................................................ */
-/* Ajax */
+/* Handling browser incompatibilities */
 
 /**
  * Create XMLHttpRequest object in cross-browser way
@@ -88,6 +88,31 @@ function createRequestObject() {
 }
 
 
+/**
+ * Insert rule giving specified STYLE to given SELECTOR at the end of
+ * first CSS stylesheet.
+ *
+ * @param {String} selector: CSS selector, e.g. '.class'
+ * @param {String} style: rule contents, e.g. 'background-color: red;'
+ */
+function addCssRule(selector, style) {
+	var stylesheet = document.styleSheets[0];
+
+	var theRules = [];
+	if (stylesheet.cssRules) {     // W3C way
+		theRules = stylesheet.cssRules;
+	} else if (stylesheet.rules) { // IE way
+		theRules = stylesheet.rules;
+	}
+
+	if (stylesheet.insertRule) {    // W3C way
+		stylesheet.insertRule(selector + ' { ' + style + ' }', theRules.length);
+	} else if (stylesheet.addRule) { // IE way
+		stylesheet.addRule(selector, style);
+	}
+}
+
+
 /* ............................................................ */
 /* Support for legacy browsers */
 

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index b1e80ef..ac335b6 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -480,6 +480,18 @@ our %feature = (
 		'override' => 0,
 		'default' => [0]},
 
+	# Enable and configure ability to change common timezone for dates
+	# in gitweb output via JavaScript.  Enabled by default.
+	# Project specific override is not supported.
+	'javascript-timezone' => {
+		'override' => 0,
+		'default' => [
+			'local',     # default timezone: 'utc', 'local', or '(-|+)HHMM' format,
+			             # or undef to turn off this feature
+			'gitweb_tz', # name of cookie where to store selected timezone
+			'datetime',  # CSS class used to mark up dates for manipulation
+		]},
+
 	# Syntax highlighting support. This is based on Daniel Svensson's
 	# and Sham Chukoury's work in gitweb-xmms2.git.
 	# It requires the 'highlight' program present in $PATH,
@@ -3733,14 +3745,19 @@ sub git_footer_html {
 		      qq!           "!. href() .qq!");\n!.
 		      qq!</script>\n!;
 	} else {
+		my ($jstimezone, $tz_cookie, $datetime_class) =
+			gitweb_get_feature('javascript-timezone');
+
 		print qq!<script type="text/javascript">\n!.
-		      qq!window.onload = function () {\n!.
-		      (gitweb_check_feature('javascript-actions') ?
-		      qq!	fixLinks();\n! : '').
-		      # last parameter to onloadTZSetup must be CSS class used by format_timestamp_html
-		      qq!	var tz_cookie = { name: 'gitweb_tz', expires: 14, path: '/' };\n!. # in days
-		      qq!	onloadTZSetup('local', tz_cookie, 'datetime');\n!.
-		      qq!};\n!.
+		      qq!window.onload = function () {\n!;
+		if (gitweb_check_feature('javascript-actions')) {
+			print qq!	fixLinks();\n!;
+		}
+		if ($jstimezone && $tz_cookie && $datetime_class) {
+			print qq!	var tz_cookie = { name: '$tz_cookie', expires: 14, path: '/' };\n!. # in days
+			      qq!	onloadTZSetup('$jstimezone', tz_cookie, '$datetime_class');\n!;
+		}
+		print qq!};\n!.
 		      qq!</script>\n!;
 	}
 
@@ -3946,7 +3963,13 @@ sub git_print_section {
 
 sub format_timestamp_html {
 	my $date = shift;
-	my $strtime = '<span class="datetime">'.$date->{'rfc2822'}.'</span>';
+	my $strtime = $date->{'rfc2822'};
+
+	my (undef, undef, $datetime_class) =
+		gitweb_get_feature('javascript-timezone');
+	if ($datetime_class) {
+		$strtime = qq!<span class="$datetime_class">$strtime</span>!;
+	}
 
 	my $localtime_format = '(%02d:%02d %s)';
 	if ($date->{'hour_local'} < 6) {