timezone problem

[Kagamin]

Qian Xu Wrote:

> Hi All,
> 
> I am fighting with date time conversion and have a problem right now:
> I want to convert a local timestamp to UTC timestamp.
> So I have to get the time zone information.
> However in some countries (ie. German, US), the offset is not constant,
> because of daylight saving issue.

Even windows doesn't have this kind of heuristics. The only solution is to keep all timestamps in UTC and leave local time representation only for user eyes and don't care about its precision.
See also http://www.codeproject.com/KB/datetime/dstbugs.aspx