Print a pdf with a date

Hi,

I'm trying to create a PDF that will show the date the document was opened and allow printing only.

So I create a text field and through Javascript show the date. The problems is that when I use security to lock the document and enable printing only it also "locks" the date on the text button and it doesn't change. The same behaviour happens when I add a date field to the header.

This happens in Acrobat X and also in DC.

Many thank for any help

David