Periodic Shifting Lock

I'm a delivery agent for UPS. On the package, I've been given instructions to drop off the package at a mail reception building accessible only through a "Periodic Shifting Lock," which I assume means that the password will change periodically. I've been given today's password, which is Scrutiny. On the keypad, however, there are only numbers! I've got to get in before it changes, I don't have another code.

Hint 1:

I need to think positive

Hint 2: