Is that ok
No. If you needed to turn the water on, to fill a pool, for one hour, would YOU stand by the valve for an hour, so you could turn it off? Or would you decide that the water needed to be turned on at 3:15:00 and off at 4:15:00? Would you turn the water on, lay in the sun, drink beer and snooze, while the water ran, and then turn it off at the required time?