New moon and the start of the months...

What signs or seasons role does the moon play?

Ex 12:2 This month (HODESH) shall be for you the beginning of months.

The answer is that the Hebrew word for month (Hodesh) itself indicates a connection to the moon. We can see this connection in a number of instances in which Hodesh (month) is used interchangeably with the word "Yerah", the common Biblical Hebrew word for moon, which by extension also means "month". For example:

"...in the month (Yerah) of Bul,
which is the Eighth month (Hodesh)..." (1 Kings 6:38)

"...in the month (Yerah) of Ethanim... which is the Seventh month (Hodesh)..." (1 Kings 8:2)

Another proof that Hodesh is related to the moon (Yerah) is the phrase "A Hodesh (month) of days" (Gen 29:14; Nu 11:20-21) [meaning a period of 29 or 30 days] which is equivalent to the phrase "A Yerah (month/ moon) of days" (Dt 21:13; 2 Ki 15:13). Clearly then Hodesh is related to "Yerah", which itself literally means "moon".

Ps 104:19 He created the moon for Mo'adim [appointed times]
So when the Psalmist tells us that God created the moon for Mo'adim [appointed times] he means that the moon was created to determine the time of the Mo'adim of Yehovah, that is, the Biblical Holidays.

The primary meaning of Hodesh (month) is actually "New Moon" or "New Moon Day" and it is only by extension that it came to mean "month", that is, the period between one New Moon and the next. This primary meaning is preserved in a number of passages such as 1Sam 20:5 in which Jonathan says to David "Tomorrow is the New Moon (Hodesh)". Clearly, in this verse Hodesh is used to refer to the specific day on which the month begins and not the entire month. Another passage which uses Hodesh in its primary sense is Ez 46:1 which talks about "The Day (Yom) of the New Moon (Ha-Hodesh)". Clearly in this verse Hodesh (New Moon) is a specific event and the beginning of the month is the day on which this event (New Moon) occurs.

"Hodesh" (New Moon), is derived from the root H.D.SH. meaning "new" or "to make new/ renew". The Crescent New Moon is called Hodesh because it is the first time the moon is seen anew after being concealed for several days at the end of the lunar cycle.

In ancient societies people worked from dawn to dusk and they would have noticed the Old Moon getting smaller and smaller in the morning sky. When the morning moon had disappeared the ancient Israelites would have anxiously awaited its reappearance 1.5-3.5 days later in the evening sky. Having disappeared for several days and then appearing anew in the early evening sky they would have called it the "New Moon" or "Hodesh" (from Hadash meaning "New").

Ps 81:3 [Heb. 81:4] "Blow on a horn for the Hodesh (New Moon)
On the Keseh (Full Moon) for the Day of our Hag (Feast)."

In the Bible, Feast (Hag) is a technical term which always refers to the three annual pilgrimage-feasts (Matzot, Shavuot, Sukkot; see Ex 23; Ex 34). New Moon Day (Hodesh) is never classified as a "Pilgrimage-Feast" so Keseh/ Hag can not possibly be synonymous with New Moon Day (Hodesh). It has further been suggested that Keseh refers to the Biblical holiday of Yom Teruah (Day of Shouting), which always falls out on New Moon Day. However, the Bible describes Yom Teruah as a Moed (appointed time) and never as a Hag (Pilgrimage-Feast) so Keseh/ Hag can not refer to Yom Teruah either.

Keseh is related to the Aramaic word "Kista" and the Assyrian word "Kuseu" which mean "full moon" This fits in perfectly with the description of Keseh as the day of the Hag since two of the three Pilgrimage-Feasts (Hag HaMatzot and Hag HaSukkot) are on the 15th of the month, which is about the time of the Full Moon!

God uses the sun and moon to establish days, months, years, and also His appointed observances, Genesis 1:14. A critical component to His calendar is the new moon, which starts each Biblical month.

God uses the new moon to establish moedim, or commanded observances, Psalm 104:19. Special offerings were also given on the new moons, 2Chronicles 2:4; 8:13; 23:31.

We find many references to the new moon or beginning of months in the Scriptures, including the obligation for True worshipers to observe them, Numbers 10:10; 28:11-15; 1Chronicles 23:31;2Chronicles 2:4; 8:13; 31:3; Ezra 3:5; Ezekiel 46:1, 3, 6; Colossians 2:16.

Ezekiel’s prophecy (46:3) states that new moon days will be kept in the coming Kingdom: “The people of the land shall also worship at the doorway of that gate before Yahweh on the sabbaths and on the new moons.”

Historically, new moon spotters in Israel watched for the thin crescent to establish the beginning of each month. Once seen they reported their sighting to the calendar court authorities of the Sanhedrin. Note what one authority says, “Originally, the New Moon was not fixed by astronomical calculation, but was solemnly proclaimed after witnesses had testified to the reappearance of the crescent of the moon,” Encyclopaedia Judaica, Vol. 12, p. 1039.

Deuteronomy 16:1: “Observe the month [chodesh, new moon] of Abib and keep the Passover…” Here, the word “observe” in the Hebrew is shamar and also means “look narrowly for, search” (No. 8104 in Strong’s). The Holladay Concise Hebrew and Aramaic Lexicon defines it as watching in the sense of looking. Vine’s Complete Expository Dictionary of Old and New Testament Words includes the definitions “mark, watchman, wait, watch, look narrowly.” The command is to look for, wait for, watch and mark the new moon.

Vine’s says, “Chodeshmeans ‘new moon,’ ‘month.’ The word refers to the day on which the crescent reappears.” The Theological Wordbook of the Old Testamentsays of (c)hodesh, “Although this word properly means ‘new moon,’ it is commonly used as an equivalent to our word ‘month’ because the month began when the thin crescent of the new moon was first visible at sunset.”

The International Standard Bible Encyclopedia says hodhesh (chodesh) means “‘new,’ ‘fresh.’ As the Hebrews reckoned their months from the actual first appearance of the young crescent, hodhesh is most frequently translated ‘month’ ” (Vol. 1, p. 303). The verb form of (c)hodesh is hadash, a primitive root meaning to rebuild, renew, repair, refresh. This gives us additional proof as to what constitutes a new moon.

According to Gesenius Hebrew-Chaldee Lexicon the word hodesh derives from a word which means to be new, or to polish a sword. Etymologists have observed that the basic sense is that of cutting and polishing. And the significance of newness relates to a polished sword. The new moon resembles a scimitar or curved sword.

The New Brown Driver Briggs Gesenius says chodesh is rooted in the meaning of conceal, as in “to conceal behind a curtain.” A full moon is anything but concealed. A crescent, on the other hand, is nearly all concealed by a curtain of darkness except for just a curved sliver of light along the right edge.