Sporadic Countdown Timer
.timer {
color:red;
border:none;
font-family:verdana;
font-size:16pt;
font-weight:bold;
border-right-color:#FFFFFF
}
<body onLoad="startCount();">
<span class="timer"><span id="counter">431</span></span>
<script>
var timer;
function startCount()
{
timer = setInterval(count, 100); // 200 = 200ms delay between counter changes. Lower num = faster, Bigger = slower.
}
function count()
{
var do_wait = Math.ceil(4*Math.random()); // for "sporadic effect", we generate a random number between 1 and 4
if (do_wait == 4) { // now, we only decrement the counter if the random number = 4 --- otherwise we don't do anything.
var rand_no = Math.ceil(9*Math.random()); // 9 = random decrement amount. Counter will decrease anywhere from 1 - 9.
var el = document.getElementById('counter');
var currentNumber = parseFloat(el.innerHTML);
var newNumber = currentNumber - rand_no;
if (newNumber > 0) {
el.innerHTML = newNumber;
} else {
el.innerHTML = "Sold Out"; // This message is displayed when the counter reaches zero.
}
}
}
</script>
</body>