I'm looking for a battery powered hose bib sprinkler timer that has up to a 12 hour "on" (duration) setting. All models I look at allow you to only set the duration of watering from 1 to 120 minutes, then set a frequency of say every X hours or Y days.

What I'm trying to do is to use one as a master control valve to control water to above ground temporary sprinklers connected by garden hoses watering hydroseeded areas around my property. I want these to only run during the day light hours, say 7AM to 7PM. I have my permanent underground sprinkler timer set to only water at night so as to not compete for water resources while I'm trying to keep my hydroseed moist in the sun.

I need to set my hydroseed (temporary hose bib) timers to run every four hours for 25 minutes or so to keep the ground moist. I have eight of these, so they use up all of the four hours before the "system" cycles back to the first timer again. No need to run at night... in fact problematic due to night time water contention issues mentioned above. Problem is that all available battery powered sprinkler timers I can find only allow you to set a frequency of 4 hours that continuously cycles 24 hours a day. Thus my idea of a master control valve... a separate timer before each individual zone's timer to turn on water only from 7AM to 7PM... as said above, I can only find models that have 2 hour max duration. I can't set frequency to 2 hours with duration of 2 hours as a work around, as this would simply cause the water to be on during the night time also.

Anyone know of a timer that is made that would handle this problem? Or of another work around?