There is a corruption that came in from Babylon that has found its way into many Christian churches. This article is brief. I'm sure you can find more.

Genesis 1:16 "And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also."

That is the quote from the KJV. Here is what the Hebrew actually says.

Genesis 1:16 "And God made two great lights; the greater light to rule the day, and the lesser light to rule the night, the stars."

The word month is normally translated from the Hebrew word chodesh. However the translators took it upon themselves to change the word to moon in any verse that had a religious event for the context. We should always support the original text meaning. Here is an example. One can search for "moon" and "sabbath" to see.

Isa 66:23 "And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith Yahweh."

Where you see the words "new moon" should be "new month". The Hebrew word there is chodesh. As you do your study do an Englishman's search for H2320 chodesh. You should find that in most verses the word is translated as month. You can do this search in e-Sword in the KJV+ by searching H2320 and then just read down the list.

The same corruption continued in one verse in the new testament as well. The Greek word translated moon is G4582. The Greek word translated month is G3376. Here is how the verse should read based on the Greek word G3561. Take a look at the root words that make up the compound word.

Colossians 2:16 "Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new month, or of the sabbath days".

When people make use of the moon to determine dates or times it is corruption from Babylon.

Gospel Minutes.org