Convert UTC to local time with NSDateFormatter

Question

I am getting the following string from a server in my iOS app:

20140621-061250

How can I convert it to the local time?

Answer 1

To get your string into a NSDate, you would use a NSDateFormatter like this:

NSString *myDateAsAStringValue = @"20140621-061250"
NSDateFormatter *df = [[NSDateFormatter alloc] init];    
[df setDateFormat:@"yyyyMMdd-HHmmss"];
NSDate *myDate = [df dateFromString: myDateAsAStringValue];

You may want to read this post about working with Date and Time

EDIT:

To parse it as UTC you have to add the line:

[df setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];

Also, when you print it with NSLog, if you are using the same NSDateFormatter, you will get the input string as output (since you apply the inverse of the parsing function).

Here is the full code, for parsing and for getting the output with a standard format:

//The input
NSString *myDateAsAStringValue = @"20140621-061250";

//create the formatter for parsing
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
[df setDateFormat:@"yyyyMMdd-HHmmss"];

//parsing the string and converting it to NSDate
NSDate *myDate = [df dateFromString: myDateAsAStringValue];

//create the formatter for the output
NSDateFormatter *out_df = [[NSDateFormatter alloc] init];
[out_df setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssz"];

//output the date
NSLog(@"the date is %@",[out_df stringFromDate:myDate]);