UIDatePicker with 15m interval but always exact time as return value

I've got a UIDatePicker in Time mode with an interval of 15 minutes.

Let's say it's 7:22PM. The value that the date picker shows per default is the current time rounded to the next higher/lower value, in this case, it's 7:15PM. If the user interacts with the date picker, the value that's shown is also the value returned. However if there hasn't been any user interaction and I get the time with [UIDatePicker date] the return value is the exact current time, i.e. 7:22 to stick with开发者_如何学运维 the example.

Is there any way to always get the value that's actually shown on the date picker instead of the current unrounded time, even if the user hasn't explicitly picked a value?

I've already tried to set the picker manually with [UIDatePicker setDate:[NSDate date]] but that doesn't change the behavior.

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I've modified @ima747 's answer for Swift 3/4 and as an extension of UIDatePicker. picker.clampedDate

extension UIDatePicker {
    /// Returns the date that reflects the displayed date clamped to the `minuteInterval` of the picker.
    /// - note: Adapted from [ima747's](http://stackoverflow.com/users/463183/ima747) answer on [Stack Overflow](http://stackoverflow.com/questions/7504060/uidatepicker-with-15m-interval-but-always-exact-time-as-return-value/42263214#42263214})
    public var clampedDate: Date {
        let referenceTimeInterval = self.date.timeIntervalSinceReferenceDate
        let remainingSeconds = referenceTimeInterval.truncatingRemainder(dividingBy: TimeInterval(minuteInterval*60))
        let timeRoundedToInterval = referenceTimeInterval - remainingSeconds
        return Date(timeIntervalSinceReferenceDate: timeRoundedToInterval)
    }
}

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This isn't a perfect solution but it works for me. I've taken it from another post and modified it to accept different values.

- (NSDate*)clampDate:(NSDate *)dt toMinutes:(int)minutes {
    int referenceTimeInterval = (int)[dt timeIntervalSinceReferenceDate];
    int remainingSeconds = referenceTimeInterval % (minutes*60);
    int timeRoundedTo5Minutes = referenceTimeInterval - remainingSeconds; 
    if(remainingSeconds>((minutes*60)/2)) {/// round up
        timeRoundedTo5Minutes = referenceTimeInterval +((minutes*60)-remainingSeconds);            
    }
    return [NSDate dateWithTimeIntervalSinceReferenceDate:(NSTimeInterval)timeRoundedTo5Minutes];
}

Feed it an input date and a minute value (taken from the UIDatePicker.minuteInterval in the case of this thread) and it will return a time clamped to that interval which you can feed to the picker.

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@ima747 is right if I've changed date picker's default value then it's working fine and if I've read date from picker control without onChange then it's returning wrong date value.
But I've checked that, date picker control have set default date (current date and may be it use nearest time milliseconds) If I set it to custom date and also set time to any date and 1:00:AM so now my time picker always open with 1:00:AM instead of current time