IOS: calculate the time difference between the two. ios calculates the time difference between the two.

IOS: calculate the time difference between the two. ios calculates the time difference between the two.
UIButton * nameButton = [UIButton buttonWithType: UIButtonTypeCustom];

NameButton. frame = CGRectMake (0,200, self. view. frame. size. width, 100 );

NameButton. backgroundColor = [UIColor orangeColor];

[Self. view addSubview: nameButton];

NSCalendar * calendar = [NSCalendar currentCalendar];

NSDate * starDate = [NSDate dateWithTimeIntervalSince1970: 1513142700]; // start time

NSDate * endDate = [NSDate dateWithTimeIntervalSince1970: 1513146300]; // End Time

Unsigned int unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;

NSDateComponents * d = [calendar components: unitFlags fromDate: starDate toDate: endDate options: 0];

[NameButton setTitle: [NSString stringWithFormat: @ "% ld hour % ld minute % ld second", (long) [d hour], (long) [d minute], (long) [d second] forState: 0];