How to create a simple JavaScript countdown timer? |A Simple JavaScript Countdown - JavaScript / Java

This JavaScript tutorial shows up the algorithm to make a simple countdown timer on your web pages, only with a few code lines.

<script type="text/javascript">

var millisecs_per_day=86400000

// set countdown time in milliseconds

// put desired day as arguments to Date.UTC

// in the order:

// year, month (remember January is 0), day of month, offset from GMT

// NOTE: we are using the offset because that represents midnight

// (beginning of the day) in a specific timezone

var countdown_time=Date.UTC(2008,7,8,-8);

// get the current time and convert to milliseconds

var now=new Date();

var now_millisecs=now.valueOf();

var day_cnt= Math.ceil(( countdown_time - now_millisecs)/86400000 )

// display the number of days left (or since)

if ( day_cnt > 1 )

{

// multiple days to go

document.write( day_cnt + " days to go")

}

else if ( day_cnt == 1 )

{

// one day to go

document.write( day_cnt + " day to go")

}

else if ( day_cnt == 0 )

{

// it's today

document.write( "today")

}

else if ( day_cnt == -1 )

{

// one day ago

document.write( day_cnt + " day ago")

}

else

{

// multiple days ago

document.write( day_cnt + " days ago")

}

</script>