[TYPO3-english] Error using strftime and TSFE

[Bartbogdan]

Hi all,

Using the following code:
  30 = TEXT
  30.data = TSFE:fe_user|user|date_of_birth
  30.strftime = %e %B %G

PHP will throw the following error:
typo3 strftime() expects parameter 2 to be long

How can I circumvent this error?
Apparantly the timestamp given by TSFE:fe_user|user|date_of_birth is a 
string. So how can I make it such that is is converted to long?

Best regards,

Bart