Description:
------------
While switching a calendar script from PHP4 to PHP5 I noticed the script takes multiple times as long to complete in PHP5 than it did in PHP4.

The problem seems to be date() and mktime() functions.

I did not notice any other PHP5 related performance issues. Scripts that do not use date() or mktime() run very fast.

Reproduce code:
---------------
test.php:

<?
  for ($i=0;$i<100000;$i++)
  {
    date('d');
  }
?>

Now check this script with both PHP4 and PHP5:

time php4 test.php
time php5 test.php

Expected result:
----------------
The script should take about the same time in both PHP4 and PHP5

Actual result:
--------------
time php4 test.php

real    0m0.286s
user    0m0.034s
sys     0m0.252s

time php5 test.php

real    0m25.252s
user    0m18.579s
sys     0m5.615s