We can find the hours between two dates by using NSDateFormatter. NSDateFormatter provides formatting and conversion methods for NSDate objects. In below code, I have used formatter to convert the start date and end date into hours and minutes where "hh" stands for hours and "mm" stands for minutes.

I have also used NSTimeInterval to get the time interval between two dates. Once we get the time interval then we convert it into numbers of hours by dividing it by 3600.

Below code is used to show number of hours between two dates.

    NSString *startTime=@"2:30 AM";// time from
    NSString *endTime=@"8:40 AM"; //time to
    
    NSDateFormatter *formatter=[[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"hh:mm a"]; 
    NSDate *startDate = [formatter dateFromString:startTime];
    NSDate *endDate = [formatter dateFromString:endTime];
    NSLog(@"times are %@ %@",startDate ,endDate);
    NSTimeInterval timeBetween = [endDate timeIntervalSinceDate:startDate];// use to show time interval between time
    NSInteger noOfhours=timeBetween/3600; //converting into hours
    NSLog(@"number of hours  are %ld",(long)noOfhours);