mcal_days_in_month

[seg]

My server is running PHP 4.3.11

I am trying to count the days of the month. I found the function mcal_days_in_month:
http://us3.php.net/manual/en/function.mcal-days-in-month.php

When I try the below code, I get the error:
"Fatal error: Call to undefined function: mcal_days_in_month() in ..."

Is this function deprecated?

<?php
$year = 2005;
$month = 10;

 $month_days = mcal_days_in_month($month, mcal_is_leap_year($year));

echo "Month: " . $month . "<br>";
echo "Year: " . $year . "<br>";
echo "Number of days: " . $month_days . "<br>";

?>

[devinemke]

you must enable the MCAL extension to use any of those functions. the installation requirements are described on the MCAL Functions page in the manual.