Method to change Page Permissions

We have a business requirement to shut down change access to a particular function for a two week period every year.  To do so today our security champion opens 3 different permission lists (call them X,Y and Z), edits the pages on the authorized components and marks them as display only.

This isn't particularly difficult or time consuming, but we were hoping to find a way to set up an App Engine job to do this automatically at the beginning of the two week period.

We've tried putting a SQL step in the App Engine as such:

UPDATE PSAUTHITEM

SET DISPLAYONLY = 1