JavaScript: Show Difference between to date, as remaind time. (what about same day and before)
<p>I want to show the difference between today and selected date time to show the remained time. </p>

<p>I used the solution mentioned in stack overflow. But I have problem about today!
When the selected day is today, or before, I mean, when the difference (<code>diffDays</code>) is not positive, I get wrong result. How can I manage this? </p>

<pre><code> $("#ServiceTime").change(
    function (e) {
        var firstDate = $(this).val();
        var secondDate = new Date();
        var diffDays = firstDate.getTime() - secondDate.getTime();
        var date = new Date(diffDays);
        var str = '';
        str += date.getUTCDate()-1 + " days and ";
        str += date.getUTCHours() + " hours and  ";
        str += date.getUTCMinutes() + " minutes";
        str += "remained...";
        $("#remainedHourToService").html(str);
        });
</code></pre>

<p>UPDATED:
I can not use <code>abs</code> by itself, if user select two past day, again he will see '1 day and 58 minutes and... ' but I want '0 days and 0 minutes.... remained'. </p>