n日後の日時を求めたい

// n日後の日時をもとめる
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDate *now = [NSDate date];

NSDateComponents *sevenDays = [[NSDateComponents alloc] init];
[sevenDays setDay:7];

NSDate *sevenDaysLater = [calendar dateByAddingComponents:sevenDays toDate:now options:0];

NSLog(@"seven days later: %@", sevenDaysLater); // => seven days later: 2010-04-11 22:45:55