Time difference between end time and start time

Date / Time Handling in web applications

... for inspiration ..., above URL content owns TWO examples in regard to
calculate HOURS from two time fields, one for MySQL and as PHP code.

and in this forum

https://asprunner.com/forums/topic/28469-Guide-21--Calculation-of-days-between-two-dates

For insperation. Set variables acording to your needs. The code goes in the Javascript OnLoad event for the corresponding page.

var ctrlDate = Runner.getControl(pageid,'TimeOut');
var CD = Runner.getControl(pageid,'TimeIn');

var DO = new Date(CD.getValue());
var DOP = Date.parse(DO) ;

var CT = new Date(ctrlDate.getValue());
var dp = Date.parse(CT) ;

var TT = Runner.getControl(pageid,'Totaltime');
var cl = Runner.getControl(pageid,'closed');

// get total seconds between the times
var delta = Math.abs(dp - DOP) / 1000;

// calculate (and subtract) whole days
var days = Math.floor(delta / 86400);
delta -= days * 86400;

// calculate (and subtract) whole hours
var hours = Math.floor(delta / 3600) % 24;
delta -= hours * 3600;

// calculate (and subtract) whole minutes
var minutes = Math.floor(delta / 60) % 60;
delta -= minutes * 60;

// what's left is seconds
var seconds = delta % 60;

//tto =(days)+" day(s) "+(hours)+" hr(s) "+(minutes)+" min "+(seconds)+" sec "

function func(){
var CT = new Date(ctrlDate.getValue());
var dp = Date.parse(CT) ;

tto =(hours)+" hr(s) "+(minutes)+" min "
TT.setValue(tto);
cl.setValue(1);
};

CD.on('keyup', func);
ctrlDate.on('keyup', func);