First of all, it must be clear that the moon, as a satellite of the earth, is a celestial body that does not emit light. Only when the sun shines on the moon and the irradiated light is reflected to the earth can human beings observe it with the naked eye. In other words, as long as the moon's light is reflected to the earth, we can see it directly at any time, including during the day. However, when the sun and the moon are located on both sides of the earth, the side facing the sun is daytime and the side facing the moon is night. At this time, the sun can't shine on the moon, so we can't see the moon during the day. When the moon and the sun are on the same side of the earth, we can see the moon during the day.
However, even if the moon can be seen during the day, it is absolutely impossible to see the full moon. The full moon will only happen when the earth doesn't stop the sun from shining on the moon, but during the day, part of the sun will shine on the earth anyway, so the sun can't shine on the whole surface of the moon, so we can't see the full moon.
Sometimes the sun and the moon are on the same side of the earth, and we can't see them, which is related to the intensity of light.
When the moon and the sun are on the same side of the earth, if the sunlight we see is too strong to cover the sunlight reflected by the moon, we can't see it anyway. Only when the sun bracelet glows softly can we see the moon, so experienced friends know that it is easiest to see the moon and the sun at the same time on the road in the morning and at dusk.
However, whether it is visible or not, the moon itself has not changed. In addition to early morning and dusk, there is also the scattering effect of the atmosphere on the sun's light, which is constantly changing with the weather.