how do I set an existing NSDate's time?

Question

how do I set an existing NSDate\'s time?

That is I have a date (say current date/time), but then want to set this to a specific time (e.g. 11.23am) say.

Answer 1

NSDate *date = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar];
NSDateComponents *components = [gregorian components: NSUIntegerMax fromDate: date];
[components setHour: 7];
[components setMinute: 59];
[components setSecond: 17];

NSDate *newDate = [gregorian dateFromComponents: components];

I use NSUIntegerMax instead of specific OR-combined bit masks because it's easier, but if you want to specify which data components to receive, be my guest.