How would you explain to someone that it's possible to have more than one full moon in a month?

A moon is a natural satellite of a planetary body. It revolves around that body - a planet or asteroid. Our Moon is the only natural satellite of Earth.

Why does our Moon shine?

"shines" because it reflects the Sun's light. At times, our Moon reflects so much light that it makes viewing parts of the night sky challenging!

The possibility of occurring more than one full moon in a month can be proved by comparing single day of moon with the number of days of earth.

Explanation:

It is known that a single day of moon is equal to 14 days of earth. The full moon occurs when sunlight falls directly on moon or we can say the starting of a day in the moon.

So as the moon rotates slowly the direction of sun deviates from the moon and we can see that the size of the moon is reducing and finally no moon day means a day ended in the moon.

So as a single day of moon occurs after every 14 days of earth, it can be concluded that a month of 31 days can observe two full moon days as it has two 14 days interval in that month.