Anyone know of a routine or algorithm that would generate a new maybe unique 1-8 position value based on date?

I have an app with a high-level user ID in a user table, protected by an encrypted password. *Sometimes* we have to give users the login password so they have access to higher-powered functions we can walk them through. Problem is, the password is static and some users have elected to remember the password and log-in that way all the time.

So what I want is to be able to change the Password or Login-In dynamically in my app's start up routine.

For instance:

07-07-2000: Login = ADMIN12, Password = Hus02380
07-08-2000: Login = ADMIN12, Password = 382JAS8s
07-09-2000: Login = ADMIN12, Password = %^#12ks3

... or ..

07-07-2000: Login = 9874jas4, Password = fishCAKE
07-08-2000: Login = jjfd93nd, Password = fishCAKE
07-09-2000: Login = __03981K, Password = fishCAKE

Get the idea?