Pump Exerciser logic

Does anyone have any suggestions how one might write ladder logic in RSlogix5k to exercise an otherwise idle pump on a weekly basis?
...if the pump is not run for XX days the system will run the pump for XX minutes...

Any suggestions would be appriciated

I assume there is an output to a contactor that turns on the pump?

If so, if that output isn't on, start a timer (or a series of timers and counters based on how long you wish the idle period to be).

Once the timer or counter is done, turn the output on for that "warm up" time.

Once again.. Forget the timer. Every time the pump shuts off, grab the real-time clock from the CPU, and save it.

Scan to see if "(Current_Day - Last_Run_Day) > Max_Down_Days". If so, run the pump for a while. When it drops out, the system will be scanning for a new value.