You can use the NSCalendar and NSTimezone classes. The following code segment demonstrates retrieving the current hour and minute. Extending it to retrieve other date components is straight-forward -
long hour;
long minute;
NSCalendar *cal=[NSCalendar currentCalendar];
NSDate *now=[NSDate date];
NSTimeZone *tz=[NSTimeZone timeZoneWithName:@"America/Chicago"];
[cal setTimeZone:tz];
NSDateComponents *comp=[cal components:NSHourCalendarUnit|NSMinuteCalendarUnit fromDate:now];
hour=[comp hour];
min=[comp minute];