-[__NSDate timeIntervalSinceReferenceDate]: message sent to deallocated instance? - ios

Question

I am trying to implement calendar. I have one label for year and two buttons for incrementing and decrementing year from calendar. I am getting this exception
(-[__NSDate timeIntervalSinceReferenceDate]: message sent to deallocated instance 0x147165f0)
while clicking button(increment or decrement)my requirement is if i click right button my year should increase as well as if i click left button my year should decrease. my exception line is
date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0];
could you please help to resolve this issue. this is my code
- (void)viewDidLoad
{
[super viewDidLoad];
date = [NSDate date];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"YYYY"];
NSString *stringFromDate = [formatter stringFromDate:date];
yar1.text=stringFromDate;
}
- (IBAction)right:(id)sender {
NSCalendar *cal = [NSCalendar currentCalendar];
date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"YYYY"];
NSString *stringFromDate = [formatter stringFromDate:date];
yar1.text=stringFromDate;
}
- (IBAction)left:(id)sender {
NSCalendar *cal = [NSCalendar currentCalendar];
date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"YYYY"];
NSString *stringFromDate = [formatter stringFromDate:date];
yar1.text=stringFromDate;
}

Answer 1

Above code looks fine and I tried in sample app, its working fine. Did you synthesize your date property? Also please cross check if your property is of type strong.