Online alarm clock for 3:30 am
Before handing the generator check to the next person, you can leave a 3:30 am alarm ready for their first visit to the DOC hut. That gives the changeover a clear time instead of relying on a sleepy conversation or a note seen too late. The half-hour before 4:00 am can cover a brief handover: where the fuel is, what sounded unusual, and what must be checked on arrival.
For this generator duty, the alarm page needs to remain active and the phone must stay awake until it sounds. If the phone sleeps first or the browser is closed, the generator check will receive no alarm from this page. Keeping the phone connected to power, with its sleep setting adjusted for the wait, reduces the chance that the incoming person misses the agreed departure.
Whoever takes over should allow for the road to a remote DOC hut, not just the check itself. At 3:30 am, an unsealed access road may be dark, wet, or slower after overnight weather, and stock or wildlife can appear without much warning. Work backwards from the expected driving time, add a modest buffer, and keep the route details with the handover notes.