Time and Dates can be a real pain when it adding and subtracting. Below is the code using the "JavaScript Math Object" that makes it easier to deal with.
"Javascript onload event of the page calculations are needed"
var DO = new Date(CD.getValue()); //date opened
var DOP = Date.parse(DO) // Grab value and covert it to 'ms' so it is an usable number instead of a string
var dp = Date.parse(d) // Grab value and covert it to 'ms' so it is an usable number instead of a string
// 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;
=(days)+" day(s) "+(hours)+" hr(s) "+(minutes)+" min "+(seconds)+" sec "
[color="#FF0000"]TO.setValue(tto);
Red of course are your own varables..