The unit consists of a digital timer with 4 outputs.
First you set the time and the day of the week and then program the watering schedule. Determine, the day, thje time of day, and the amount of time or duration. Each output is controlled individually.
Ideally plants in the garden will receive 1-2 inches of rain per week. That's about 1-2 hours of watering. On some rows I am using soaker hoses so that I only water the plants and not the wide spaces between rows.
For my bean and corn crops I am using rotating sprinklers which allow me to cover a wider area.
Because I am using a battery powered timer with its own internal clock, I can tell the system to only water at night, when usage by the community is at a minimum.