Я нашел хорошее решение.
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDateComponents * components = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSSecondCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit
fromDate:[NSDate date]];
NSString * stringDate = [NSString stringWithFormat:@"%d-%d-%d %d:%d:%d", components.year, components.month, components.day, components.hour, components.minute, components.second];
Другое решение
NSDate *date = [NSDate date];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
NSTimeZone *zone = [NSTimeZone localTimeZone];
[formatter setTimeZone:zone];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSLog(@"Date %@",[formatter stringFromDate:date]);