This allows a pump to be switched on periodically for a set time to irrigate plants in pots or bags. The irrigation can be specified to operate in the “day only” mode or it can have a different interval set for day and night. For example, you could set it to irrigate for 4 minutes every 1 hours 35 minutes during the day and for 4 minutes every 5 hours at night. (or not at all during the night)
Alternatively, it can be set to come one once every day at the same time. This could even be used to operate lighting (instead of irrigation) for indoor crops.
If the pump is a mains voltage pump then a relay will be needed to re-power the 24V DC so that it can supply mains power to the pump. Your distributor should have convenient relay boxes available for this.