NSDateComponents of an NSDate

There's an example in the Apple docs, Listing 3: Getting a date’s components:

NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc]
                         initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents =
                    [gregorian components:(NSDayCalendarUnit | 
                                           NSWeekdayCalendarUnit) fromDate:today];
NSInteger day = [weekdayComponents day];
NSInteger weekday = [weekdayComponents weekday];

Note that you have to 'or' together the calendar units you want in the call of the components method.

using NSCalendar's method:

- (NSDateComponents *)components:(NSUInteger)unitFlags fromDate:(NSDate *)date

like:

unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit;
NSDate *date = [NSDate date];


NSCalendar * cal = [NSCalendar currentCalendar];
NSDateComponents *comps = [cal components:unitFlags fromDate:date];