[uf-discuss] [possibly slightly OT] timezones - where do you to find accurate timezone data? (TZ is not always accurate!)

[Michael MD]

[related to hCalendar and pretty much anything calendar-related]

I have a couple of questions about timezones and TZ.

does anyone here know of a good source of up-to-date timezone data?

so far on my website for local events timezones have not been used and
events have been assumed to be in the timezone of the city/country they are
posted in.

This historically was the only workable way to do it without accurate
timezone data to do conversions.
(spraci.com has been doing events listings online since 1994 so there can
also be legacy issues with data here)

I see problems however when presenting this data in formats related to iCal
(such as hCalendar) when applications expect the correct timezone.

To fix this I need to find a source of accurate and up-to-date timezone
information for coutries and cities worldwide
- so far I haven't been able to find anything quite good enough (apart from
unaffordable commercial services that claim to provide this kind of data)

Most things use the TZ timezones but these are at times inaccurate (due to
the fact that politicians sometimes change daylight saving changeover dates
with very little notice!) and those inaccuracies will have to be somehow
translated too.