The phase of the Moon affects the number of stars visible in the night sky by creating sufficient background light that our eyes cannot discern fainter stars. So stargazing during a full Moon is rather pointless.
The stars are visible in the night sky because the sun is brighter than the stars, and at night, of course, there is no sun, so you can see the stars only in the night sky
Strictly speaking, the exact moment of "Full Moon" is the only time when the sun and moon can not be
in the sky at the same time ... the Full moon rises just as the sun sets.
At every other moon...