Web alarm clock for 12:32 a.m.
As you finish checking the rice field bunds and head away, set the alarm for 12:32 am so the late-night irrigation check does not slip past you. The alert leaves 28 minutes before 1:00 am, enough time to return to the field, inspect the water level, and prepare the next section without treating the round hour as the actual deadline.
Because you are leaving the rice field after setting the time, consider what will happen to the phone before the alert is due. Keep this browser alarm running where the phone can stay awake, connected to power if needed, and loud enough to hear from nearby. If the browser is closed or the phone sleeps first, the alarm may not sound, and the irrigation check could be missed. A separate phone alarm is a sensible backup when you will be far from the screen.
On a humid Philippine night, leave a little time to step outside and notice whether the air feels heavy or a breeze has started across the field. At 12:32 am, moisture on paths and bunds can make footing less certain, so carry a light, wear shoes with grip, and approach the irrigation point steadily rather than rushing through the dark.