Re: [PATCH] strbuf: let strbuf_addftime handle %z and %Z itself

From: Ulrich Mueller <ulm@gentoo.org>
Date: Jun 13, 2017, 10:31 UTC
Message-ID: <22847.48875.297447.531147@a1i15.kph.uni-mainz.de>
In-Reply-To: <c7532160-53eb-a0c5-94e6-483aadf0cfc5@web.de>

>>>>> On Tue, 13 Jun 2017, René Scharfe wrote:

Show 6 quoted lines

> Am 12.06.2017 um 21:02 schrieb Ævar Arnfjörð Bjarmason:
>> Which gives me a pretty good idea of where the people who are making
>> my colleges / collaborators who are making commits all over the world
>> are located, for the purposes of reinforcing the abstract numeric
>> mapping with a best-guess at what the location might be, or at least
>> something that's close to the actual location.

> Half the time this would be off by a zone in areas that use daylight
> saving time, or you'd need to determine when DST starts and ends, but
> since that depends on the exact time zone it will be tricky.

And sometimes it would be impossible since DST rules differ between hemispheres. For example, there is Europe/Berlin vs Africa/Windhoek, or America/Halifax vs America/Santiago.

> You could use military time zones, which are nice and easy to convert:
> Alpha (UTC+1) to Mike (UTC+12) (Juliet is skipped), November (UTC-1) to 
> Yankee (UTC-12), and Zulu time zone (UTC+0).  Downside: Most civilians
> don't use them. :)

Yeah, that would ensure complete confusion. :) You'd have "Quebec" for -0400 whereas the city of Quebec is in zone -0500. Similar for "Lima" denoting +1100.

> Also there are no names for zones that have an offset of a fraction
> of an hour.

There are also zones like Pacific/Tongatapu which have +1300 (and +1400 in summer).

All in all I think that Jeff's suggestion makes most sense: Expand %Z to the timezone name for the -local case, when the name is readily available. Otherwise, expand it to the empty string.

Ulrich