How to convert NSTimeInterval to hours, minutes

 NSDate *now = [NSDate date];  

    NSString *dateString = [self.dateFormatter stringFromDate:now];

    NSTimeInterval todaysDiff = [[self.dateFormatter dateFromString:dateString] timeIntervalSinceNow];

    NSTimeInterval dateDiff = lastDiff - todaysDiff;

    

    

    div_t h = div(dateDiff, 3600);

    int hours = h.quot;

    // Divide the remainder by 60; the quotient is minutes, the remainder

    // is seconds.

    div_t m = div(h.rem, 60);

    int minutes = m.quot;

    timeTag.text = [NSString stringWithFormat:@" %d:%d",hours,minutes];