I have no idea why this extremely basic piece of code sets null values.
NSDate *currentTime = [NSDate date];
[datePicker setMinimumDate:currentTime];
[datePicker setMaximumDate:[currentTime dateByAddingTimeInterval:kSecondsInYear]];
NSLog(@"cur: %@, min: %@, max: %@",currentTime,datePicker.minimumDate,datePicker.maximumDate);
Output: cur: 2011-09-09 16:18:18 GMT, min: (null), max: (null)
Found the problem, I was setting the min/max date in the initwithnib method. When I changed it to the viewDidLoad method it worked fine. whoops.