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iosobjective-cnsdatedst

How to show date with timezone for date, relevantly to defined country/zone?

I need to show a date in concrete time zone including DST (European time). App will be used in Lithuania, so time zone is +3 at summer and +2 at other time. The thing is, I have just a list of dates and I don't know how to show +3 for summer dates and +2 for other dates. Currently, I have time zones:

// Eastern European Summer Time UTC + 3 hours
NSTimeZone *timeZoneWithDst = [NSTimeZone timeZoneWithAbbreviation:@"EEST"];

//Eastern European Time UTC + 2 hours
NSTimeZone *timeZoneWithoutDst = [NSTimeZone timeZoneWithAbbreviation:@"EET"];

But how to loop through my list of dates and calculate should I add +3 or +2 to date?

UPDATE Finally I got it working by applying Martin R. suggestion to use time zone by name, not by abbreviation. In this way, date with this time zone handles DST automatically. Here's my code for converting dates:

NSTimeZone *TimeZone = [NSTimeZone timeZoneWithName:@"Europe/Vilnius"];
NSInteger seconds = [myTimeZone secondsFromGMTForDate:someDate];
NSDate *result = [NSDate dateWithTimeInterval:seconds sinceDate:someDate];
Solution

  • To convert an NSDate to a string representation, use NSDateFormatter. By default, it uses the local time zone. To display the date according to a concrete time zone, you can set

    NSTimeZone *tz = [NSTimeZone timeZoneWithName:@"Europe/Vilnius"];
[dateFormatter setTimeZone:tz];

    (According to http://www.timezoneconverter.com/cgi-bin/findzone, the time zone for Lithuania is "Europe/Vilnius".)