Due to the Moon's being the closest object to Earth, and the nature of its orbit, it can sometimes become visible during the day.
Moon Phases
Moon
The Simple Reason Why We Can See The Moon During The Day
The moon — A complete guide to Earth's companion
How Can You See the Sun and the Moon at the Same Time? - Universe Today
Moon - Wikipedia
Astro-Challenge: Adventures in Daytime Astronomy - Universe Today
Where Is The Moon During The Day? How, When And Where You Can See An 'Afternoon Moon' This Week From Home
Everything you've ever wanted to know about the Moon
What Color is the Moon? - Universe Today
Why Do We Sometimes See The Moon During The Day?
Phases of the Moon App for iPhone and Android - Universe Today
What is a blue moon and when will the next one occur?