Rebase problems

I'm using git for a project I'm working on alone (and I really like it), so I could rebase a lot, if I hadn't the following problems.

There's a file containing the timestamp which gets compiled in, so the executable can show it's version. Sometimes, I need to set it couple of times a day, sometimes only once a week. For each such timestamp I create a tag, so I can track it to the source easily. The timestamp is an important piece of information, so I put the containing file under version control. The downside is that I often get a conflict in this file halting my rebase. Is there a way how to ignore or automatically resolve all conflicts in this file (any resolution strategy is fine, as it will be overwritten anyway).

The second problem is problem of cygwin. While most of the operations git run in fractions of seconds, the most trivial rebase may take one minute or alike. Any idea what different things rebase do?