Check out the video of how it works

Granted, in my implementation I added a field for time deductions, but I have commented it out in the code. If you add a duration, just change the script to use that field. Also, please make sure to add the fields to the required parameters for the event. I would hate for someone’s code to stop working because a field was removed from the form.

This code is for the Start, End, and Deduct (if you have it) on change events:

// Get End and Start
var start = crmForm.all.actualstart.DataValue;
var end = crmForm.all.actualend.DataValue;
// Can't calculate without any data
if (start==undefined || start==null || end==undefined || end==null) {
	return;
}

// Get 1 day in milliseconds
var one_minute=1000*60;

// Get time in days...
var time = (end-start)/one_minute;

/*
// Get the deduction
var deduct = crmForm.all.it_timeentry_deduct.DataValue
if (deduct!=undefined && deduct!=null)
{
  time = time - deduct;
}
*/

// Can't be less than 0.
if (time<0) time=0;

// Set the duration
crmForm.all.actualdurationminutes.DataValue = time;

This code is for the onchange event of the Duration field:

var start = crmForm.all.actualstart.DataValue;
var duration = crmForm.all.actualdurationminutes.DataValue;
// Can't calculate without any data
if (start==undefined || start==null || duration==undefined || duration==null)
{
	return;
}

var end = start;
end.setMinutes(end.getMinutes()+duration);

/*
var deduct = crmForm.all.it_timeentry_deduct.DataValue
if (deduct!=undefined && deduct!=null)
{
  end.setMinutes(end.getMinutes()+deduct);
}
*/

crmForm.all.actualend.DataValue=end;

To preset the duration, start time and end time, I added the following script to the form’s onload event

var CRM_FORM_TYPE_CREATE = 1;
var CRM_FORM_TYPE_UPDATE = 2;

if (crmForm.FormType==CRM_FORM_TYPE_CREATE)
{
	var duration = 10;
	var start = new Date();
	crmForm.all.actualstart.DataValue = start;
	crmForm.all.actualdurationminutes.DataValue = duration;
	var start = crmForm.all.actualstart.DataValue;

	var end = start;
	end.setMinutes(end.getMinutes()+duration);

	crmForm.all.actualend.DataValue=end;
}

If you have any questions about this implementation or would like assistance implementing it somewhere, please post a comment and let us know.