Swift 4 Date Picker Wrong Value Using Minuteinterval

UIDatePicker odd behavior when setting minuteInterval

Okay so I was able to change the behavior by explicitly setting the UIDatePicker date value to the date rounded to the minute interval using the following code:

- (void) handleUIControlEventTouchDown:(id)sender
{
    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    // Set the date picker's minute interval.
    NSInteger minuteInterval  = [sender tag];

    // Setting the date picker's minute interval can change what is selected on
    // the date picker's UI to a wrong date, it does not effect the date
    // picker's date value.
    //
    // For example the date picker's date value is 2:31 and then minute interval
    // is set to 10.  The date value is still 2:31, but 2:10 is selected on the
    // UI, not 2:40 (rounded up) or 2:30 (rounded down).
    //
    // The code that follow's setting the date picker's minute interval
    // addresses fixing the date value (and the selected date on the UI display)
    // .  In the example above both would be 2:30.
    datePicker.minuteInterval = minuteInterval;

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    // Calculate the proper date value (and the date to be selected on the UI
    // display) by rounding down to the nearest minute interval.
    NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:NSMinuteCalendarUnit fromDate:date];
    NSInteger minutes = [dateComponents minute];
    NSInteger minutesRounded = ( (NSInteger)(minutes / minuteInterval) ) * minuteInterval;
    NSDate *roundedDate = [[NSDate alloc] initWithTimeInterval:60.0 * (minutesRounded - minutes) sinceDate:date];

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    // Set the date picker's value (and the selected date on the UI display) to
    // the rounded date.
    if ([roundedDate isEqualToDate:datePicker.date])
    {
        // We need to set the date picker's value to something different than
        // the rounded date, because the second call to set the date picker's
        // date with the same value is ignored. Which could be bad since the
        // call above to set the date picker's minute interval can leave the
        // date picker with the wrong selected date (the whole reason why we are
        // doing this).
        NSDate *diffrentDate = [[NSDate alloc] initWithTimeInterval:60 sinceDate:roundedDate];
        datePicker.date = diffrentDate;
        [diffrentDate release];
    }
    datePicker.date = roundedDate;
    [roundedDate release];
}

Pay attention to the part where the UIDatePicker's date is set twice. It was fun figuring that out.

Anyone know how to turn the animation off for the call to minuteInterval? The phantom scrolling when clicking 5 then 10 is a little unsightly.

UIDatePicker with 5 min interval get date on appear with interval

you could check the date and round it to your needs like this:

override func viewDidLoad() {
    super.viewDidLoad()

    let calendar = Calendar.current
    var dateComponents = calendar.dateComponents([.month, .day, .year, .hour, .minute], from: datePicker.date)
    guard var hour = dateComponents.hour, var minute = dateComponents.minute else {
        print("something went wrong")
        return
    }

    let intervalRemainder = minute % datePicker.minuteInterval
    if intervalRemainder > 0 {
        // need to correct the date
        minute += datePicker.minuteInterval - intervalRemainder
        if minute >= 60 {
            hour += 1
            minute -= 60
        }

        // update datecomponents
        dateComponents.hour = hour
        dateComponents.minute = minute

        // get the corrected date
        guard let roundedDate = calendar.date(from: dateComponents) else {
            print("something went wrong")
            return
        }

        // update the datepicker
        datePicker.date = roundedDate
    }
}

feel free to ask if anything is unclear!

How to limit date selection on UIDatePicker

Configure your picker with a minuteInterval

datePicker.minuteInterval = 5

will make the picker increment in 5 minute intervals.

You can set the minute interval to whatever interval you need, but the number must evenly divide into 60

UIDatePicker setting incorrect time when configured to use a 30 minute interval

Use NSDateComponents to get and manipulate the hour and minute of a date. Here's how I did it:

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit) //Need to pass all this so we can get the day right later
                                           fromDate:[NSDate date]];
[components setCalendar:calendar]; //even though you got the components from a calendar, you have to manually set the calendar anyways, I don't know why but it doesn't work otherwise
NSInteger hour = components.hour;
NSInteger minute = components.minute;

//my rounding logic is maybe off a minute or so
if (minute > 45)
{
    minute = 0;
    hour += 1;
}
else if (minute > 15)
{
    minute = 30;
}
else
{
    minute = 0;
}

//Now we set the componentns to our rounded values
components.hour = hour;
components.minute = minute;

// Now we get the date back from our modified date components.
NSDate *toNearestHalfHour = [components date];
self.datePicker.date = toNearestHalfHour;

Hope this helps!

---

Related Topics