I have time interval e.g. "01:30:00" as the string. Now I want to convert this string to a valid DateTime in javascript to manipulate. for example: add 1 hour.
I solved my problem.
first Get current DateTime by new Date()
second use .toDateString()
third attach my time interval e.g. "01:30:00".
new Date().toDateString() + ' ' + "01:30:00" // Mon May 09 2016 01:30:00
Now use moment.js
var t = moment(new Date().toDateString() + ' ' + "01:30:00");
ّFinaly add for example 1 hour by moment().add()
var finalTime = t.add(60, 'minutes').format("hh:mm");
demo
var stringTimeInterval = "01:30:00";
var t = moment(new Date().toDateString() + ' ' + stringTimeInterval);
document.getElementById("demo").innerHTML = t.add(60, 'minutes').format("hh:mm:00");
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.13.0/moment.min.js"></script>
<div id="demo"></div>