Hi,
In JavaScript you could do something like;
var DateTimeRegex = /(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d)/;
var d1 = DateTimeRegex.exec(DateTimeField1.rawValue);
if (d1 !== null)
{
var fromDate = new Date(d1[1], d1[2]-1, d1[3], d1[4], d1[5]);
}
var d2 = DateTimeRegex.exec(DateTimeField2.rawValue);
if (d2 !== null)
{
var toDate = new Date(d2[1], d2[2]-1, d2[3], d2[4], d2[5]);
}
const millisecondsPerMinute = 1000 * 60;
const millisecondsPerHour = millisecondsPerMinute * 60;
const millisecondsPerDay = millisecondsPerHour * 24;
var interval = toDate.getTime() - fromDate.getTime();
var days = Math.floor(interval / millisecondsPerDay );
interval = interval - (days * millisecondsPerDay );
var hours = Math.floor(interval / millisecondsPerHour );
interval = interval - (hours * millisecondsPerHour );
var minutes = Math.floor(interval / millisecondsPerMinute );
console.println(days + " days, " + hours + " hours, " + minutes + " minutes");
This assumes that the values in DateTimeField1 and DateTimeField2 are valid, which means the rawValue will be in a format like 2009-03-15T18:15
Regards
Bruce