How do I get an ISO 8601 date on iOS?
ios, iso8601, nsdate, nsdateformatter
Solution
Use `NSDateFormatter`:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSLocale *enUSPOSIXLocale = [NSLocale localeWithLocaleIdentifier:@"en_US_POSIX"];
[dateFormatter setLocale:enUSPOSIXLocale];
[dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];
[dateFormatter setCalendar:[NSCalendar calendarWithIdentifier:NSCalendarIdentifierGregorian]];
NSDate *now = [NSDate date];
NSString *iso8601String = [dateFormatter stringFromDate:now];
And in Swift:
let dateFormatter = DateFormatter()
let enUSPosixLocale = Locale(identifier: "en_US_POSIX")
dateFormatter.locale = enUSPosixLocale
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
dateFormatter.calendar = Calendar(identifier: .gregorian)
let iso8601String = dateFormatter.string(from: Date())
Problem
It's easy enough to get the ISO 8601 date string (for example, `2004-02-12T15:19:21+00:00`) in PHP via `date('c')`, but how does one get it in Objective-C (iPhone)? Is there a similarly short way to do it? Here's the long way I found to do it: ``` NSDateFormatter* dateFormatter = [[[NSDateFormatter alloc] init] autorelease]; dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ssZ"; NSDate *now = [NSDate date]; NSString *formattedDateString = [dateFormatter stringFromDate:now]; NSLog(@"ISO-8601 date: %@", formattedDateString); // Output: ISO-8601 date: 2013-04-27T13:27:50-0700 ``` It seems an awful lot of rigmarole for something so central.