Convert Time to GMT/Get GMT Offset

by salman

HTML

<p>Input</p>
<input type="text" name="time" id="time" value="07/21/2011 17:00">
<p>GMT Value</p>
<input type="text" name="gmtime" id="gmtime" readonly>
<p>GMT Offset (hours)</p>
<input type="text" name="offset" id="offset" readonly>

CSS

p {
    font-family: monospace;
}
input {
    font-family: monospace;
    width: 300px;
}

JavaScript

document.getElementById("time").onchange = function() {
    var d = new Date(this.value);
    if (isNaN(d) == false) {
        document.getElementById("gmtime").value = d.toUTCString();
    }

}
document.getElementById("time").onchange();
document.getElementById("offset").value = (new Date()).getTimezoneOffset() / 60;