Here's why:

* Moon Phases: The moon's phases are caused by the changing angles of sunlight reflecting off its surface as it orbits the Earth. A full moon occurs when the entire sunlit side of the moon faces Earth.

* Sun and Moon Position: A full moon is directly opposite the sun in the sky. This means that when the full moon is visible, the sun is on the other side of the Earth, making it nighttime.

While you might see a sliver of a crescent moon during the day, you'll never catch a full moon in the daytime sky.