How many days until X-Y-Z date?
Expanding on schnaader's answer, here is a one-liner function that takes a date string as a parameter but only returns the number of days:
<?php
function days_until($date){
return (isset($date)) ? floor((strtotime($date) - time())/60/60/24) : FALSE;
}
?>
Don't treat dates as integers. Use your database, which has good support for dealing with calendars/time.
select datediff("2009-11-12", now())
<?php
$cdate = mktime(0, 0, 0, 12, 31, 2009);
$today = time();
$difference = $cdate - $today;
if ($difference < 0) { $difference = 0; }
echo floor($difference/60/60/24)." days remaining";
?>
PHP 5.3 has introduced the DateTime class that implements a 'diff' function. See http://www.php.net/manual/en/datetime.diff.php