Almost all of the timers we have covered here come with a small user manual, which explains how to set up your timer. For automatic timers, such as the Intermatic P1353ME 3-Circuit Pool/Spa Digital Time Switch, you simply have to input the time and the day that you prefer the pool pump timer to turn on and off. Many automatic devices come with multiple operating modes. Once you have figured out the number of modes on your device, you can easily set your digital pump accordingly. For mechanical devices, the manufacturer provides users with pins that can be placed around the clock dial for whenever the device needs to operate. Simply place your pins at ‘on’ and ‘off’ clips after loosening these clips with a screwdriver. The timer will operate the pump accordingly at the set time.