There is no set time that works for all systems or every zone.
Each rotor head has different GPM nozzles, that can be changed.
The best way to find your time setting is to place many shallow cans (Tuna) around the zone area.
Check the water level in the can, after the zone has run.
You should have 1/2"-3/4" per watering. (two days in the summer, one day in the winter)
Adjust the time or change the nozzles to meet the 1/2-3/4" amount.
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