NSDate *today = [[NSDate alloc] init];

    NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

    NSDateComponents *components = [[NSDateComponents alloc] init];

    [components setDay:80];

    NSDate *endDay = [cal dateByAddingComponents:components toDate:today options:0];

    NSLog(@"%@",endDay);