Random Date generator for Objective C.

RandomDateGenerator.m

/**
 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.

 @param days date range between today and minimum date to generate
 @return random date
 @see http://stackoverflow.com/questions/10092468/how-do-you-generate-a-random-date-in-objective-c
 */
- (NSDate *)generateRandomDateWithinDaysBeforeToday:(NSUInteger)daysBack {
    NSUInteger day = arc4random_uniform((u_int32_t)daysBack);  // explisit cast
    NSUInteger hour = arc4random_uniform(23);
    NSUInteger minute = arc4random_uniform(59);

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

    NSDateComponents *offsetComponents = [NSDateComponents new];
    [offsetComponents setDay:(day * -1)];
    [offsetComponents setHour:hour];
    [offsetComponents setMinute:minute];

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

    return randomDate;
}

Hey, I made a swift version here. https://gist.github.com/edmund-h/2638e87bdcc26e3ce9fffc0aede4bdad

NSUInteger day = arc4random_uniform((u_int32_t)daysBack);  // explisit cast should be

NSUInteger day = arc4random_uniform((u_int32_t)daysBack) + 1;  // explisit cast

If you don't add 1, you will randomly get time in the future because arc4random_uniform generates numbers from 0 to max -1