Rounding of NSdate to nearest hour in iOS

Question

I have data in the format

time: 13:52, 10:30, 11:48

etc

I would like to round to the nearest hour.

like for 13:52 -> 14:00 , 10:30 -> 11:00 and 11:48 -> 12:00.

How can I do that with NSDate?

Answer 1

Use this method

- (NSDate*) nextHourDate:(NSDate*)inDate{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *comps = [calendar components: NSEraCalendarUnit|NSYearCalendarUnit| NSMonthCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit fromDate: inDate];
    [comps setHour: [comps hour]+1]; //NSDateComponents handles rolling over between days, months, years, etc
    return [calendar dateFromComponents:comps];
}

This will give you the date in next hour for the inDate

Answer 2

Here's a Swift 3.0 implementation that gets the nearest hour, using a Date extension:

extension Date {
    func nearestHour() -> Date? {
        var components = NSCalendar.current.dateComponents([.minute], from: self)
        let minute = components.minute ?? 0
        components.minute = minute >= 30 ? 60 - minute : -minute
        return Calendar.current.date(byAdding: components, to: self)
    }
}

Answer 3

 func nextHourDate() -> NSDate? {
    let calendar = NSCalendar.currentCalendar()
    let date = NSDate()
    var minuteComponent = calendar.components(NSCalendarUnit.MinuteCalendarUnit, fromDate: date)
    let components = NSDateComponents()
    components.minute = 60 - minuteComponent.minute
    return calendar.dateByAddingComponents(components, toDate: date, options: nil)
}

Answer 4

Using components is not reliable due to a couple of reasons:

1. Seconds are not taken into account
2. When adding seconds, rarely it misses one second

The most reliable way I found in Swift 4.* is:

extension Date {
    func nearestHour() -> Date {
        return Date(timeIntervalSinceReferenceDate:
                (timeIntervalSinceReferenceDate / 3600.0).rounded(.toNearestOrEven) * 3600.0)
    }
}

Answer 5

Use the Below code. It must help for you.

  NSString *dateString=@"17:15";
    NSArray *strings = [dateString componentsSeparatedByString:@":"];

int firstPart=[[NSString stringWithFormat:@"%@",strings[0]] intValue];
int lastPart=[[NSString stringWithFormat:@"%@",strings[1]] intValue];

NSLog(@"LAST:%d",firstPart);

if (lastPart>0) {

    int output=firstPart+1;



    NSString *finalOutput=[NSString stringWithFormat:@"%d:00",output];

     NSLog(@"OUTPUT:%@",finalOutput);
}
else
{
     NSLog(@"OUTPUT:%@",dateString);
}