It is important to reset the timer after your electric power has been off.

Remove the front cover from the control head on top of the black filter.

Push the red button in to allow the black wheel to turn. Use the
black wheel to adjust the time and then release the red button.

If you have both a chlorinator and a softener, set the chlorinator
to the actual time and the softener two hours later. This is to allow
the backwash cycle for each to run through its complete sequence.