Answer :

1 month, or 29 days. (It is funny that this is a question because we had to takes 2 pages of notes today in school all about he moon) Hope I helped!
AL2006

The moon completes its orbit around the Earth in 27.32 days (rounded).

That's NOT the length of the cycle of the moon's phases.  The time from
any phase until the next appearance of the same phase is 29.53 days.