> There is risk of short pulses of bright light; lightning, vehicles,
> torches.

You can mitigate those by putting the sensor down a tube, so that
it sees only a small part of the sky or ambient

Output of a sensor will change fairly rapidly and noticeably. They
don't adjust like our eyes do and are much better at indicating
absolute rather than relative. For example a solar panel's output
can be seen dropping by the minute at dusk. You wouldn't need
too many samples brighter/darker than those before to determine
dawn/dusk confidently

> I've no plans for a nearby supernova.

Glad to hear it. We're not at home to Mr Gamma Ray Burst and
I already have more neutrinos than I know what to do with
--=20
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