> I wanted to use the timezone long names for users to indicate their current > timezone/DST but many of the major cities are missing from the list. How > does somebody from say, America/Dallas, indicate their timezone? I'm > assuming that they would select the nearest city to their current location > which in this case would be America/Chicago. Are there any DST issues I > should look out for seeing as Dallas and Chicago are in different states and > at different ends of the same timezone? Would it be better to use a GMT > offset in this situation and if I do, how does DateTime work out DST?
I'm half awake here but I'll get it a try. Olson timezones are not per city but per observance 'region' including historic observances for an area. It can be confusing because a city name is used to denote a geographic region. This makes some sense as city names are a lot more likely to make sense to someone unfamiliar with a particular area. If there were different observances then there should be a separate entry in the Olson DB. Here is an explanation of the basic concept: http://www.mindspring.com/~gwil/tconcept.html When in doubt use UTC, in fact you should probably be normalizing to UTC anyways, as it will save yourself a lot of hassle down the road. Cheers, -J --
