Time Zone Maps and References

So What's the Problem With Timezones?

The problem with time zones is that a simple time zone map can't really tell you what time it is someplace, because Daylight Savings Time screws everything up. Not only do some places (countries, states) observe it while others in the same time zone don't, many places "spring forward" and "fall back" at different times of the year. UNIX stores rules about who switches when in system files you can read about in man page section tzfile(5); but instead of worrying over whether my OS's version of these rules is up to date (I know of at least some places where it's not) and giving out information that looked misleadingly "accurate", I made a a dynamic timezone map that is deliberately vague in design. If you want something more precise, use this handy page to get exact times in major cities. Their timezone/DST rules file seems up-to-date.

For a firsthand peek at the zoneinfo files, you can look right at the Net-BSD dist of them, here. Incidentally, I've heard that the last word in what-time-it-is-where (short of calling the governments of everywhere in question) is to be had from the International Air Transportation Association (IATA), altho I don't happen to see anything helpful on their web site.