Midnight format in timesheet not working

Question

I am using Standard XI to create a timesheet that is filable. However, midnight is showing at 00:00 am not 12:00 am. Anything in that 12 am hour is 00.  Is there a script I can add to change it?
I tried to download a free version of Pro to see if I could get something to work with that but it says my computer already has a program that is similar and won't download but I have no idea what that other program would be.
I don't see anyway to add a document level script using Standard XI. What would I try next?

Answer 1

As I have it scripted right now a start time of 12:00 am and an end time of 1:00 am equals -11.00 hours not 1.00 hour. What script would I have to add so the calculation is correct?
Here is the script I have right now:
// start time
// Start time field name
var cStartName = "start1mon1";
// Start time format:
var cStartFormat = "HH:MM";
// end time
// end time field name
var cEndName = "end1mon1";
// End time format:
var cEndFormat = "HH:MM";
// some conversion functions
// function to convert time string to minutes
function Time2Num(cTime, cFormat) {
// convert time string to minutes
// convert time string to date object
var oDate = util.scand("mm/dd/yyyy " + cFormat, "01/01/1970 " + cTime);
// convert date object to number of milliseconds
var nTime = oDate.getTime();
// convert milliseconds to minutes and return value
return Math.round(nTime / (1000 * 60));
} // end Time2Num function
function Num2Time(nMinutes) {
// convert time string to Hours and Minute
// hours in nMinues
var nHrs = Math.floor(nMinutes / 60);
// remainder minutes from hours in nMinutes
var nMins = nMinutes / 60;
// return formatted time string
return nHrs, nMins;
} // end Num2Time
// end conversion functions
// perform the calculation using the fields:
// get the values of the fields
var cStartTime = this.getField(cStartName).value;
var cEndTime = this.getField(cEndName).value;
// clear the value
event.value = "";
// test for not null time strings
if(cStartTime != "" && cEndTime != "") {
// compute the time difference in minutes
nDiff = Time2Num(cEndTime, cEndFormat) - Time2Num(cStartTime, cStartFormat);
event.value = Num2Time(nDiff);
} //end not null values
I have no prior knowledge of JavaScript, only what I have found here on the forums and a lot of luck. I would appreciate help on this problem. Thanks!