Hi there,
I have a two Time fields on a Workers Time Sheet form
Start Time (start_time1)
End Time (end_time1)
and a numeric field accounting for minutes the worker took as a break.
Break Time (break1)
I need to calculate the TOTAL hours worked by End Time - Start Time - Break Time.
eg. 8:00 AM - 2:00 PM with a 1 hour break = 5 hours working

You can see on the screenshot attached the code is calculating (2 - 8 - 1 = -7)
It actually should convert 2pm to 14 (14 - 8 - 1 = 5)
Below is the code that is not working because you will see that on the line labelled HERE
it outputs the End Time as 2:00 and not 2:00 PM
Is there something wrong in using this line to get the selected time:

var end_time = $("#field_end_time1").val();
Any help would be most appreciated.
(

   function adjust_total() {
   // On the change event of the start and end times, change the total time worked
   var total_label = "#field_total_extra1";
   var start_time = $("#field_start_time1").val();
   var end_time = $("#field_end_time1").val();
   var break_time = $("#field_break1").val();
      end_time = end_time.slice(0,5);
      start_time = start_time.slice(0,5)

      if(start_time !="" && end_time !=""){
		console.log("Original end time = " + end_time); // HERE
         start_time = start_time.split(":");
         end_time = end_time.split(":");
		 var starttime_hours = start_time[0];
		 var starttime_mins = start_time[1];
		 var endtime_hours = end_time[0];
		 var endtime_mins = end_time[1];

         var startDate = new Date(0, 0, 0, starttime_hours, starttime_mins, 0);
         var endDate = new Date(0, 0, 0, endtime_hours, endtime_mins, 0);
         var diff = endDate.getTime() - startDate.getTime();
         var hours = Math.floor(diff / 1000 / 60 / 60);
         diff -= hours * 1000 * 60 * 60;
         var minutes = Math.floor(diff / 1000 / 60);
         minutes = (minutes < 9 ? "00" : minutes);
         numb = hours + (minutes/60) - (break_time/60);
         $(total_label).val(numb);
         $(total_label).change();
      } 
	  
   }