The moon during the day?

We've all seen it 1000s of times. But WHY?

Why? I'll tell you: During the day, the brightness of the sky washes out the light from the stars: a region of the sky including a bright star is only very slightly brighter than a region of the sky without a bright star, so your eye cannot notice the difference. However, the region of the sky containing the Moon is much brighter, so you can see it. You can also sometimes see Venus during the day if the conditions are right and you know exactly where to look, but anything dimmer is lost.

If you would like to know more try this link.