To use the below, call it like a normal function. There are four arguments. The first determines what you want to measure the date difference in - years, months, quarters, etc - and the allowed values of this are listed in the first few lines of the function. The next two are the dates themselves. Any valid date should work just fine. You can also use timestamps as dates, although if you do, you must set the last of the four arguments to “true”. You can call it like so:
example:
datediff(”m”,’1978-10-11′,date(”Y-m-d”))
echo datediff(’w', ‘9 July 2003′, ‘4 March 2004′, false);
function datediff($interval, $datefrom, $dateto, $using_timestamps = false) {
/*
$interval can be:
yyyy - Number of full years
q - Number of full quarters
m - Number of full months
y - Difference between day numbers
(eg 1st Jan 2004 is “1″, the first day. 2nd Feb 2003 is “33″. The datediff is “-32″.)
d - Number of full days
w - Number of full weekdays
ww - Number of full weeks
h - Number of full hours
n - Number of full minutes
s - Number of full seconds (default)
*/
if (!$using_timestamps) {
$datefrom = strtotime($datefrom, 0);
$dateto = strtotime($dateto, 0);
}
$difference = $dateto - $datefrom; // Difference in seconds
switch($interval) {
case ‘yyyy’: // Number of full years
$years_difference = floor($difference / 31536000);
if (mktime(date(”H”, $datefrom), date(”i”, $datefrom), date(”s”, $datefrom), date(”n”, $datefrom), date(”j”, $datefrom), date(”Y”, $datefrom)+$years_difference) > $dateto) {
$years_difference–;
}
if (mktime(date(”H”, $dateto), date(”i”, $dateto), date(”s”, $dateto), date(”n”, $dateto), date(”j”, $dateto), date(”Y”, $dateto)-($years_difference+1)) > $datefrom) {
$years_difference++;
}
$datediff = $years_difference;
break;
case “q”: // Number of full quarters
$quarters_difference = floor($difference / 8035200);
while (mktime(date(”H”, $datefrom), date(”i”, $datefrom), date(”s”, $datefrom), date(”n”, $datefrom)+($quarters_difference*3), date(”j”, $dateto), date(”Y”, $datefrom)) < $dateto) {
$months_difference++;
}
$quarters_difference–;
$datediff = $quarters_difference;
break;
case “m”: // Number of full months
$months_difference = floor($difference / 2678400);
while (mktime(date(”H”, $datefrom), date(”i”, $datefrom), date(”s”, $datefrom), date(”n”, $datefrom)+($months_difference), date(”j”, $dateto), date(”Y”, $datefrom)) < $dateto) {
$months_difference++;
}
$months_difference–;
$datediff = $months_difference;
break;
case ‘y’: // Difference between day numbers
$datediff = date(”z”, $dateto) - date(”z”, $datefrom);
break;
case “d”: // Number of full days
$datediff = floor($difference / 86400);
break;
case “w”: // Number of full weekdays
$days_difference = floor($difference / 86400);
$weeks_difference = floor($days_difference / 7); // Complete weeks
$first_day = date(”w”, $datefrom);
$days_remainder = floor($days_difference % 7);
$odd_days = $first_day + $days_remainder; // Do we have a Saturday or Sunday in the remainder?
if ($odd_days > 7) { // Sunday
$days_remainder–;
}
if ($odd_days > 6) { // Saturday
$days_remainder–;
}
$datediff = ($weeks_difference * 5) + $days_remainder;
break;
case “ww”: // Number of full weeks
$datediff = floor($difference / 604800);
break;
case “h”: // Number of full hours
$datediff = floor($difference / 3600);
break;
case “n”: // Number of full minutes
$datediff = floor($difference / 60);
break;
default: // Number of full seconds (default)
$datediff = $difference;
break;
}
return $datediff;
}
