I need to convert a local time attached to a Country, State/City into a GMT time for each incoming request received by our server. This must work in a multithreaded architecture, i.e; we have a fixed number of threads which process the incoming request.
Do you have a list of countries, states for the US, cities which matches
I think you will find that this problem cannot be solved simply. I am working on linking the tz name to my Global Gazetteer database of 4+ million records of populated places (& 50K ports, airports & railway stations). In many cases the solution is trivial - the whole country uses the same time zone. At the next level down, the provinces within a country use different time zones, but each province uses only one time zone. At the next level down, a province may use more than one time zone and the split may be along the lines of lower level administrative boundaries. Again, not a problem, if one has this information. Finally, there is a residue of places, where the only way to determine the time zone is to check reference sources and to assign it manually. I did this for a county in Texas recently. I am now trying to get the detailed information for the Broken Hill area. I have written a program that works through my database and assigns the name (e.g. Europe/London). I keep information on the time zone offset, DST, formal rules for change & some other information in a separate file. Still lots to do, but I am getting there. Best wishes Alan Pritchard The GLOBAL GAZETTEER: the world on file http://www.allm-geodata.com Tel: +44 (0) 1202 417 477