I have created an application in which user selects the start_time & end_time of the tasks performed in that day from datetimepicker control (CUstom format HH:mm) and the number of minutes will be calculated automatically. Now my problem is how to remove the lunch break minutes from the minutes calculated? FOr example, if user selects 12:00 to 14:00, number of minutes should be 1.5. (lunch break is from 13:00 to 13:30)