A Cocoa NSFormatter subclass for converting ISO 8601 formatted string to NSDate, and vice versa.

The parser is implemented using re2c. Thanks to re2c, it is much faster than NSDateFormatter is.

• Calendar Date
• Ordinal Date
• Week Date
• Local Time with Decimal Fractions
• Midnight
• Time Zone

• BC Date
• Basic Format of Ordinal Date Expanded Representation (Year > 9999)
• Local Time with Leap Second (Second >= 60.0)
• Time Inverval
• Duration
• Recurring Time Interval

To convert ISO 8601 string to NSDate. You can use NJISO8601DateFromString() function without any configuration.

NSDate *date = NJISO8601DateFromString(@"2011-02-27T11:03:06+09:00");

or, you can use the NJISO8601Formatter the same way as you do with NSDateFormatter.

NJISO8601Formatter *formatter = [[NJISO8601Formatter alloc] init];

NSDate *date = [formatter dateFromString:@"2011-02-07T11:03:06+09:00"];

To convert NSDate to ISO 8601 formatted string.

NJISO8601Formatter *formatter = [[NJISO8601Formatter alloc] init];

NSString *string = [formatter stringFromDate:date];

Also, you can customize output format like this:

[formatter setDateStyle:NJISO8601FormatterDateStyleWeekExtended];
[formatter setTimeZoneStyle:NJISO8601FormatterTimeZoneStyleExtended];
[formatter setFractionSeparator:NJISO8601FormatterFractionSeparatorDot];
[formatter setFractionDigits:6];
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:(8 * 60 * 60)]];