Question

How do I convert a DateTime from EST/EDT to GMT but I don’t know where the code will be ran (unknown local time zone) and also account for time savings…

Answer 1

You want TimeZoneInfo.ConvertTimeToUtc(), which allows you to pass the source time zone info as a parameter. For example:

TimeZoneInfo est = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime someDateTimeInUtc = TimeZoneInfo.ConvertTimeToUtc(someDateTime, est);

I think this will automatically handle daylight-saving time, but you’ll want to test it to be sure.