Is there a way to calculate the time it has to be on Earth at any moment in time when a person on the Moon would say their clock reads noon (i.e. a time at which a sundial on the Moon would cast no shadow)?
I would guess it has to do with the relative angle between the planes in which the Moon orbits the Earth and the Earth orbits the Sun respectively, but then how is the Moon facing the Sun at any given moment? Any ideas?
(inspired by this Tom Lehrer song)