Question

What are the names of the days on which we see a round moon and on which we see no moon at all?

Answer 1

Dear Student,
The phases of the moon do not happen on the same days each month because the moon's orbit around the Earth does not take exactly one month. The number of days between one full moon and the next full moon is 29 1/2 days.
But as far the names are concerned
Full moon Night is called Poornima.
No moon night is called Amavasya.

Regards