iOS: Simple Local Notification 3 Days Prior - ios

Question

I wrote an app that allows the user to enter a date on a date picker, and then when they tap a button it will schedule a local notification. The only issue is, the notification fires right when I tap the button. Any help is much appreciated! Here is my code:
- (IBAction)scheduleNotifButton:(id)sender {
NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];
NSDate *currentDate = [self.datePicker date];
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
[dateComponents setDay:-3];
NSDate *targetDate = [calendar dateByAddingComponents:dateComponents toDate:currentDate options:0];
UILocalNotification *localNotif = [[UILocalNotification alloc] init];
if (localNotif == nil)
return;
localNotif.fireDate = targetDate;
localNotif.timeZone = [NSTimeZone defaultTimeZone];
localNotif.alertBody = #"Event is in 3 days!";
localNotif.alertAction = nil;
localNotif.soundName = UILocalNotificationDefaultSoundName;
localNotif.applicationIconBadgeNumber = 0;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotif];
}

Answer 1

You need to use [NSCalendar dateByAddingComponents:toDate:options:] instead:
NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];
NSDate *currentDate = [self.datePicker date];
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
[dateComponents setDay:-3];
NSDate *targetDate = [calendar dateByAddingComponents:dateComponents toDate:currentDate options:0];
[dateComponents release];
...

Answer 2

If you're looking for complete code on how to schedule a notification a bit later (like say 3 seconds) here's the complete code :
NOTE : If you're inside the app you won't see a message box at the top of the screen, that might have to be handled through the UIApplication delegate.
UILocalNotification *localNotification = [[UILocalNotification alloc] init];
NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];
NSDate *currentDate = [[NSDate alloc] init];
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
[dateComponents setSecond: 3 ];
NSDate *targetDate = [calendar dateByAddingComponents:dateComponents toDate:currentDate options:0];
localNotification.fireDate = targetDate;
localNotification.timeZone = [NSTimeZone defaultTimeZone];
localNotification.alertBody = #"Notified";
localNotification.alertAction = #"Show";
localNotification.soundName = UILocalNotificationDefaultSoundName;
localNotification.applicationIconBadgeNumber = 1;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];