Lock cells after Today's date passed (VBA excel code)

Well, there will be cells that contain a reservation name before and after today's date. I want to automatically lock all cells from (D7:J7675) prior to today's date (not including today's date) so that no changes can be made unless you have administrative privileges. This is to protect the integrity of the reservation so that when the reserved thing has been used, the user cannot remove their name to illustrate that they did not use it.

I've attached a sample reservation schedule for reference as to what I mean.

Please Advise,

Thank you