How many of you guys knew right off the bat what "moons" ment

I was rewarching equestria girls with my husband and when Princess Celestia said "you have 3 days to return or the portal will be closed for 30 moons" my husband said "whats so bad about not being able to come home for 30 days?" To which I had to break the news to him that they mean moon cycles, which ment the portal would have been closed roughly 2.5 years, then he understood the gravity of it hahaha