Question

I’d like to generate a random date between two dates — for example a random date between today and 60 days from now. How do I do that?

UPDATE

Using information from the answers, I came up with this method, which I use quite often:

// Generate a random date sometime between now and n days before day.
// Also, generate a random time to go with the day while we are at it.
- (NSDate *) generateRandomDateWithinDaysBeforeToday:(NSInteger)days
{
    int r1 = arc4random_uniform(days);
    int r2 = arc4random_uniform(23);
    int r3 = arc4random_uniform(59);

    NSDate *today = [NSDate new];
    NSCalendar *gregorian = 
             [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *offsetComponents = [NSDateComponents new];
    [offsetComponents setDay:(r1*-1)];
    [offsetComponents setHour:r2];
    [offsetComponents setMinute:r3];

    NSDate *rndDate1 = [gregorian dateByAddingComponents:offsetComponents 
                                                  toDate:today options:0];

    return rndDate1;
}

Answer 1

1. Generate a random number between 1 and 60

   int r = arc4random_uniform(60) + 1;
   
   // Usage : arc4random_uniform(hi - lo + 1) + lo
   

2. Get current date

   [NSDate date];
   

3. Use NSDateComponents to subtract the random number from your days component and generate a new date.