tv.AgendaDatum:strtotime:date=`%A, %B %e, %Y`
This question has been answered by jeroenkenters. See the first response.
<?php
/* Set locale to Dutch */
setlocale(LC_ALL, 'nl_NL');
/* Output: vrijdag 22 december 1978 */
echo strftime("%A %e %B %Y", mktime(0, 0, 0, 12, 22, 1978));