NSDate from NSString adjusted to device timzone - iphone

Question

I have an NSString like this :
NSString *playTime = #"20:45";// GMT
I need to convert this string to NSDate (only hours and seconds) then adjusted to device timezone.
Example:
If user device timezone is set to GMT, I need a result like this : #"20:45";
If user device timezone is set to GMT + 2, I need a result like this : #"22:45";

Answer 1

Try this
NSString *gmtDateString = #"20:45";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"UTC"]];
[dateFormatter setDateFormat:#"HH:mm"];
//Now you have date in GMT time zone by default dateFormatter timezone would be in local time zone
NSDate *date = [dateFormatter dateFromString:dateString];
//set to local time zone
[dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
//Now you have string in localDate format
NSString *localDateString = [dateFormatter stringFromDate:date];

Answer 2

The below code will calculate the time w.r.t. local time zone.
Suppose my time zone is GMT+05:30 so the time 05:30 will become 00:00.
NSString *playTime = #"20:45";
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = #"HH:mm";
NSDate *date = [formatter dateFromString:playTime];
NSLog(#"%#",date);
Log is: 2000-01-01 15:15:00 +0000

Answer 3

Use this code for date conversion as per your requirement.
NSDateFormatter *dateFormat = [NSDateFormatter new];
[dateFormat setDateFormat:#"HH:mm"];
[dateFormat setTimeZone:[NSTimeZone localTimeZone]];
logDate = [dateFormat dateFromString:#"20:45"];
NSLog(#"Date %#",[dateFormat stringFromDate:logDate]);