NSDateFormatter seems to have the wrong month

Question

I have this block of code to read in the ISO 8601 Date/Time specification. The problem is that for some reason, the month doesn't work. Every time I convert it month is "01". What am I doing wrong?

NSDateFormatter *UTCDateFormat = [[NSDateFormatter alloc] init];
[UTCDateFormat setDateFormat:@"yyyy-MM-DD'T'HH:mm:ss'Z'"];
[UTCDateFormat setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]];
[UTCDateFormat setCalendar:[[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease]];
[UTCDateFormat setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] autorelease]];
NSLog(@"%@", [UTCDateFormat dateFromString:dateString]);

So, for example, if dateString was:

@"2002-03-12T21:13:27Z" 

my output would be:

2002-01-12 21:13:27 +0000

Things I have already tried:

• Changed MM to LL
• Tried without setCalendar/setLocale
• tried with ' around the -
• switched position of MM around to other places. It never changes anything.
• Looked all over SO and it appears to work for everyone else.

Answer 1

Try this

    [UTCDateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"];

DD is the "Day of the year" not the "Day of a month". A great source for looking up NSDateFormatter formats is this table