Translate Time Zone Names to Time ID:s

Question

I found out that iOS framework doesn’t understand proper time zone names, like "Eastern Standard Time”. If you type:

NSLog(@"EST: %@", [NSTimeZone timeZoneWithName:@"Eastern Standard Time"]);

… you get:

EST: (null)

Instead, you have to use time ID:s (a narrower area), like "America/New_York" for example:

NSLog(@"EST: %@", [NSTimeZone timeZoneWithName:@"America/New_York"]);

... then the console kindly responds:

EST: America/New_York (GMT-4) offset -14400 (Daylight)

Is there any way to translate time zone names to time ID:s? Because the web-API I’m using is giving me time zone names, not the time ID:s.

Answer 1

This is how I did it. (The stupid solution, but it works.) I used the Windows/TZID timezone mapping at unicode.org and made a method around a big dictionary.

- (NSString*) translateFromWindowsTimezone: (NSString*) timezoneName{
    NSDictionary *timezoneDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                @"Australia/Darwin", @"AUS Central Standard Time",
                                @"Asia/Kabul", @"Afghanistan Standard Time",
                                @"America/Anchorage", @"Alaskan Standard Time",
                                @"Asia/Riyadh", @"Arab Standard Time",
                                @"Asia/Baghdad", @"Arabic Standard Time",
                                @"America/Buenos_Aires", @"Argentina Standard Time",
                                @"America/Halifax", @"Atlantic Standard Time",
                                @"Asia/Baku", @"Azerbaijan Standard Time",
                                @"Atlantic/Azores",@"Azores Standard Time",
                                @"America/Bahia", @"Bahia Standard Time",
                                @"Asia/Dhaka", @"Bangladesh Standard Time",
                                @"America/Regina", @"Canada Central Standard Time",
                                @"Atlantic/Cape_Verde", @"Cape Verde Standard Time",
                                @"Asia/Yerevan", @"Caucasus Standard Time",
                                @"Australia/Adelaide", @"Cen. Australia Standard Time",
                                @"America/Guatemala", @"Central America Standard Time",
                                @"Asia/Almaty", @"Central Asia Standard Time",
                                @"America/Cuiaba", @"Central Brazilian Standard Time",
                                @"Europe/Budapest", @"Central Europe Standard Time",
                                @"Europe/Warsaw", @"Central European Standard Time",
                                @"Pacific/Guadalcanal", @"Central Pacific Standard Time",
                                @"America/Chicago", @"Central Standard Time",
                                @"America/Mexico_City", @"Central Standard Time (Mexico)",
                                @"Asia/Shanghai", @"China Standard Time",
                                @"Etc/GMT+12", @"Dateline Standard Time",
                                @"Africa/Nairobi", @"E. Africa Standard Time",
                                @"Australia/Brisbane", @"E. Australia Standard Time",
                                @"Asia/Nicosia", @"E. Europe Standard Time",
                                @"America/Sao_Paulo", @"E. South America Standard Time",
                                @"America/New_York", @"Eastern Standard Time",
                                @"Africa/Cairo", @"Egypt Standard Time",
                                @"Asia/Yekaterinburg", @"Ekaterinburg Standard Time",
                                @"Europe/Kiev", @"FLE Standard Time",
                                @"Pacific/Fiji", @"Fiji Standard Time",
                                @"Europe/London", @"GMT Standard Time",
                                @"Europe/Bucharest", @"GTB Standard Time",
                                @"Asia/Tbilisi", @"Georgian Standard Time",
                                @"America/Godthab", @"Greenland Standard Time",
                                @"Atlantic/Reykjavik", @"Greenwich Standard Time",
                                @"Pacific/Honolulu", @"Hawaiian Standard Time",
                                @"Asia/Calcutta", @"India Standard Time",
                                @"Asia/Tehran", @"Iran Standard Time",
                                @"Asia/Jerusalem", @"Israel Standard Time",
                                @"Asia/Amman", @"Jordan Standard Time",
                                @"Europe/Kaliningrad", @"Kaliningrad Standard Time",
                                @"Asia/Seoul", @"Korea Standard Time",
                                @"Indian/Mauritius", @"Mauritius Standard Time",
                                @"Asia/Beirut", @"Middle East Standard Time",
                                @"America/Montevideo", @"Montevideo Standard Time",
                                @"Africa/Casablanca", @"Morocco Standard Time",
                                @"America/Denver", @"Mountain Standard Time",
                                @"America/Chihuahua", @"Mountain Standard Time (Mexico)",
                                @"Asia/Rangoon", @"Myanmar Standard Time",
                                @"Asia/Novosibirsk", @"N. Central Asia Standard Time",
                                @"Africa/Windhoek", @"Namibia Standard Time",
                                @"Asia/Katmandu", @"Nepal Standard Time",
                                @"Pacific/Auckland", @"New Zealand Standard Time",
                                @"America/St_Johns", @"Newfoundland Standard Time",
                                @"Asia/Irkutsk", @"North Asia East Standard Time",
                                @"Asia/Krasnoyarsk", @"North Asia Standard Time",
                                @"America/Santiago", @"Pacific SA Standard Time",
                                @"America/Los_Angeles", @"Pacific Standard Time",
                                @"America/Santa_Isabel", @"Pacific Standard Time (Mexico)",
                                @"Asia/Karachi", @"Pakistan Standard Time",
                                @"America/Asuncion", @"Paraguay Standard Time",
                                @"Europe/Paris", @"Romance Standard Time",
                                @"Europe/Moscow", @"Russian Standard Time",
                                @"America/Cayenne", @"SA Eastern Standard Time",
                                @"America/Bogota", @"SA Pacific Standard Time",
                                @"America/La_Paz", @"SA Western Standard Time",
                                @"Asia/Bangkok", @"SE Asia Standard Time",
                                @"Pacific/Apia", @"Samoa Standard Time",
                                @"Asia/Singapore", @"Singapore Standard Time",
                                @"Africa/Johannesburg", @"South Africa Standard Time",
                                @"Asia/Colombo", @"Sri Lanka Standard Time",
                                @"Asia/Damascus", @"Syria Standard Time",
                                @"Asia/Taipei", @"Taipei Standard Time",
                                @"Australia/Hobart", @"Tasmania Standard Time",
                                @"Asia/Tokyo", @"Tokyo Standard Time",
                                @"Pacific/Tongatapu", @"Tonga Standard Time",
                                @"Europe/Istanbul", @"Turkey Standard Time",
                                @"America/Indianapolis", @"US Eastern Standard Time",
                                @"America/Phoenix", @"US Mountain Standard Time",
                                @"Etc/GMT", @"UTC",
                                @"Etc/GMT-12", @"UTC+12",
                                @"Etc/GMT+2", @"UTC-02",
                                @"Etc/GMT+11", @"UTC-11",
                                @"Asia/Ulaanbaatar", @"Ulaanbaatar Standard Time",
                                @"America/Caracas", @"Venezuela Standard Time",
                                @"Asia/Vladivostok", @"Vladivostok Standard Time",
                                @"Australia/Perth", @"W. Australia Standard Time",
                                @"Africa/Lagos", @"W. Central Africa Standard Time",
                                @"Europe/Berlin", @"W. Europe Standard Time",
                                @"Asia/Tashkent", @"West Asia Standard Time",
                                @"Pacific/Port_Moresby", @"West Pacific Standard Time",
                                @"Asia/Yakutsk", @"Yakutsk Standard Time", nil];
   return [timezoneDictionary objectForKey:timezoneName];
}

To use it, just type:

NSString *tzidTimezoneName = [self translateFromWindowsTimezone: someWindowsTimezoneName];

If you use this code, please make a comment about errors or missing timezones if you find any!