New and Improved JavaScript Clock
by Jeff Starr on Sunday, January 4, 2009 – 5 Responses
Earlier this year, I posted an article explaining how to implement an unobtrusive JavaScript dynamic clock. While not completely earth-shattering or cutting-edge or anything like that, the dynamic JavaScript clock has received some great feedback from users who found the script to be exactly what they were looking for. In fact, a couple of weeks ago, Bill Brown went above and beyond by taking the time to improve the script with some great new features, including a “blinking seconds separator (for kicks)” and removal of “the need for the noscript tag.” Here is the complete script sent by Bill in a recent email (with slightly reformatted markup). To try it out, simply copy and paste the following code into a blank PHP document (no editing required!):
Click here to see a working example of the script
Click here to see the text version of this code
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Unobtrusive JavaScript Dynamic Clock</title>
<script type="text/javascript">
(function() { document.getElementsByTagName('html')[0].className='scripted' })();
</script>
<style type="text/css">
#datetime {
font-family: "Courier New", monospace;
letter-spacing: 0.25em;
border: 3px solid #c00;
background: #f5f5e5;
text-align: center;
font-weight: bold;
padding: 5px 0;
}
.scripted #datetime {
border: 3px double #ccc;
background: #f5f5f5;
text-align: center;
font-weight: bold;
padding: 5px 0;
}
</style>
<script type="text/javascript">
String.prototype.pad = function(l, s, t) {
return s || (s = " "), (l -= this.length) > 0 ?
(s = new Array(Math.ceil(l / s.length)
+ 1).join(s)).substr(0, t = !t ? l : t == 1 ? 0 : Math.ceil(l / 2))
+ this + s.substr(0, l - t) : this;
};
// addLoadEvent @ http://simonwillison.net/2004/May/26/addLoadEvent/
var addLoadEvent = function (func) {
var oldonload = window.onload;
if (typeof window.onload != 'function') {
window.onload = func;
} else {
window.onload = function() {
if (oldonload) {
oldonload();
}
func();
}
}
};
// Unobtrusive JavaScript Dynamic Clock
// http://perishablepress.com/press/2008/03/04/unobtrusive-javascript-dynamic-clock/
var xClock = function () {
var xC = null, xN = null, xH = null, xI = null,
xM = null, xS = null, xT = null, AP = null;
if (!document.getElementById) return;
xC = document.getElementById("time");
if (!xC.nodeName) return;
xN = new Date();
xH = xN.getHours().toString().pad(2,'0',0);
xM = xN.getMinutes().toString().pad(2,'0',0);
xS = xN.getSeconds().toString().pad(2,'0',0);
AP = (xH >= 12) ? "PM" : "AM";
xH = (xH >= 13) ? (xH - 12) : xH;
sS = (xN.getMilliseconds() >= 500) ? ":" : "·";
xT = xH + ":" + xM + sS + xS + " " + AP;
xC.innerHTML = xT;
xI = !xI ? null : clearTimeout(xI);
xI = setTimeout(xClock, 500);
};
addLoadEvent(xClock);
</script>
</head>
<?php flush();?>
<body>
<div id="datetime">
<span id="date"><?php echo date("l, F j, Y ~ "); ?></span>
<span id="time"><?php echo date("h:i:s A", time()); ?></span>
</div>
</body>
</html>
Focused on clean code and quality content, Perishable Press is the online home of Jeff Starr, author, artist, designer, developer, and all-around swell guy. 
5 Responses
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Chiwan – #1
Hi.
This is cool. So I can I replace the clock that comes with your Apathy theme with this clock?
If that’s not possible, how do I add the “seconds” as you have on your site?
Thank you!
Chiwan
Jeff Starr – #2
Hi Chiwan, I got your email and have sent some information that may help you with this.
Cheers, Jeff
Shefik – #3
What about appending in the current timezone to the output (such as EST or EDT)?
Shefik – #4
The blinking does not work well on Mac Firefox or Safari.
Only the seconds have the bottom dot blinking (the top dot for seconds does not blink. The minutes does do not blink at all.
Jeff Starr – #5
@Shefik: Sounds like a browser issue.. I am not sure how much control external JavaScript can provide over such minutia. Perhaps there is a way to resolve the issue with (X)HTML or CSS?