How do I set the time on the Grey Box? - Intermatic WH40 - Water Heater Time Switch - NEMA 1 Indoor Steel Case - DPS

The little yellow dial has to be pulled away from the box in order to line up the silver arrow with the correct time.
Pull the whole dial towards yourself, you will notice that the yellow dial can now turn so you can line up the times that are printed on it to the correct time of day it is when you do this.
It's best to set the dial clock to the correct time of day.
Then tighten the little pointers that have the on-off words printed on them to the times you would like them to function.
If I helped you please give me a vote,Gary

You should have 2 tabs that can be positioned around the clock dial at the times you want the water heater turn and turn off. One tap will be marked "ON" and one will be marked "OFF". Put the tabs on the dial at the times that you want the heater to start and stop. Tighten securely. Once they are in place, I believe you lift the dial out slightly away from the back of the entire box and then you can rotate it until the pointer is pointing to the time of day that it is right now. Watch for AM/PM.
Lastly, if the heater is supposed to be on now, push the lever on the bottom to "ON". If the heater is supposed to be off now, push the lever on the bottom to "OFF".