Some interesting links I found that discuss time zones:
Complete timezone information for all countries. – Just as the label says
The official US time (NIST & USNO) – Displays the current time in the 10 major time zones in the United States.
Time Zone Converter – Allows a search of the various time zones in the world.
What makes time zone conversions a pain in the ass is that each jurisdiction has control over its own timezone. In some places (like California) we’re on Pacific Standard Time/Pacific Daylight Time, period, thankyouverymuch, haveaniceday.
But in places like Indiana, where every blasted county has it’s own ideas as to if it is in Central Standard Time, or Eastern Standard Time, and if the cows there can tolerate the shift between daylight savings time–well, the tz database becomes a hot mess, with things like “America/Indiana/some-random-place” littered throughout. On the other hand, most of that hot mess boils down to “this week, Knox County Indiana has decided to switch time zones from central to eastern”–which, for a UI timezone picker, doesn’t really matter. The fine folks of Knox County can just pick “Central” or “Eastern” and be done with it.
Sometimes the easiest sounding thing, like “pick a time zone”, becomes a royal pain in the neck. And even easier things like “what time is it in GMT at my location” become royally hard. It’s like that, when local politics gets involved.