JSFiddle - React, Tailwind, and code Playground

by Graham Fairweather

HTML

<input type="text" id="TDIFF_IN_SECONDS" />

JavaScript

function parseMyDate(dateString) {
    var parts = dateString.split(/[ \-:\.]/g);

    parts[1] -= 1;
    return new Date(Date.UTC.apply(undefined, parts)).getTime();
}

document.getElementById("TDIFF_IN_SECONDS").value = Math.abs(parseMyDate('2014-01-21 13:50:20.123') - 
                                                              parseMyDate('2014-01-21 12:50:20.123')) / 1000;