How Many Days Are In The Current Month

If you ever need to determine how many days are in the current month, here are a few lines of code to get you there.
Calling the rangeOfUnit method in the NSCalendar object, you specify both a small and large calendar units. In this case, a day unit within a month unit. With that information in hand, check the length of the returned range to determine how many days in the month:

  // Use today's date NSDate *today = [NSDate date];   // With a calendar object, request the day unit of the month unit NSRange dayRange = [[NSCalendar currentCalendar]    rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:today];   NSLog(@"There are %d days in the current month.", dayRange.length);

I ran this example on April 4th, 2012, here is the output:
2012-04-04 21:42:33.816 Sandbox[4862:f803] There are 30 days in the current month.