system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can we see a full moon during the daytime if we can also see the sun? (Given that the full moon is due to the reflection of the sun on the moons surface)
gpt
The geometry for this only works when the sun is near setting soon after the moon has risen or vice versa.  Because the moon, earth and sun aren't usually in a direct straight line the light can illuminate virtually the whole face that we can see in those circumstances.

In a similar fashion, a very new moon is less likely to be seen at night instead of the day because the moon has to be on the same side of the earth as the sun so that the visible hemisphere is not illuminated.