So Romanian uses the same word for both "moon" and "month". Juste like Japanese with "tsuki"! Furthermore " *mḗh₁n̥s" had also both meanings in PIE. The English terms "moon" and "month" also have the same etymology because they originate from this root.
And yet in Spanish, mes (month), is nothing like the word luna (moon). I wonder if there are similarities in the other romance languages.