[TYPO3] How to add php code into a page?

[Ronald Wiplinger]

I would like to add these lines into a page:

<?php
$dday = mktime(0, 0, 0, 3, 29, 2001);
$diff = time() -$dday;
$days = $diff / 86400;
printf( "(%d day%s young)", $days, $days == 1 ? "" :"s"); ?>

It is just a calculation of days between today and March 29, 2001.

I added above code into a pagecontent of type HTML.

What would be the correct way?

bye

R.