It is not necessarily the Moon, Dr.PM...It may be the position or the tilt of axis of the earth...or something different with the Sun. The only thing we can experience directly is a shadow. It can be the light source, it can be the object that casts the shadow, it can be the object that the shadow is casted. Something has changed. Quoting: emerald_glow
That would be the Sun, the Moon, or the Earth.
(As has been pointed out, the shape of the crescent Moon is not due to a shadow being cast by some external object; it is entirely the result of the angle the sunlight hits the Moon, as seen from the Earth).
The times of rising, setting, equinox, solstice, etc. for the Sun are documented in the same way as tables for the Moon; on paper, on sources that go back up to hundreds of years.
And the motions of the Earth (as if they could be independent of the apparent position of Sun and Moon!) are indirectly documented in navigational tables of the rise time of beacon stars.
None of these three elements could be changed without effects being obvious to millions of people.