The Scriptural month begins with the Crescent New Moon, also called First
Visible Sliver.

The Hebrew word for month (Hodesh) literally means New Moon and only by
extension the period between one New Moon and the next.

The Rabbanite Midrash relates that when YAHWEH (YHWH) said to Mosheh
(Moses) "This month (HODESH) shall be for you the beginning of months" (Ex
12,2) The Almighty pointed up into the heavens at the crescent New Moon and
said "When you see like this, sanctify! [=declare New Moon day]".

This Rabbinic fairy-tale highlights an important point, namely that The Scriptures
never come out and says we should determine the beginning of months based
on the New Moon.

The reason for this is that the term for "Month" (Hodesh) itself implies that the
month begins with the crescent New Moon.

As will be seen, this would have been obvious to any ancient Israelite present
when Mosheh (Moses) recited the prophecies of YAHWEH (YHWH) to the
Children of Israel and therefore there was no need to elucidate this concept any
more than such terms as "light" or "dark".

However, due to the long exile, we have lost the use of Scriptural Hebrew in
day to day speech. Therefore, we will have to reconstruct the meaning of
Hodesh from the usage of the word in the Scriptural text using sound linguistic
principles.

He Created the Moon for Set Apart Days

There can be no doubt that The Scriptural Set Apart Days are dependent on the
Moon.

The strongest proof of this is the passage in Psalm 104:19 which declares:

"He created the Moon for Mo'adim [Appointed Times]"

The Hebrew term Mo'adim [appointed times] is the same word used to describe
The Scriptural Set Apart Days.

Leviticus Chapter 23, which contains a catalogue of the Scriptural Set Apart
Days opens with the statement: "These are the Mo'adim [Appointed Times] of
YAHWEH (YHWH), Set Apart Convocations which you shall proclaim in their
Appointed Times [Mo'adam]".

So when the Psalmist tells us that YAHWEH (YHWH) created the Moon for
Mo'adim [Appointed Times] he means that the Moon was created to determine
the time of the Mo'adim of YAHWEH (YHWH), that is, The Scriptural Set Apart
Days.

"Hodesh" is Related to the Moon

The above verse clearly teaches us that The Set Apart Days are related to the
Moon.

But when the Torah was given, Psalm 104 had not yet been written by the
Levitical prophets, and the question still remains of how the ancient Israelites
could have known this.

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 Scriptural Hebrew
word for Moon, which by extension also means "month".

For example:

"...in the month (Yerah) of Ziv,
which is the Second month (Hodesh)..." (1Kings 6:1)

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

Another proof that Hodesh is related to the Moon (Yerah) is the phrase "A
Hodesh (month) of days" (Genesis 29:14; Numbers 11:20-21) [meaning a
period of about 30 days] which is equivalent to the phrase "A Yerah (month /
Moon) of days" (Deuteronomy 21:13; 2 Kings 15:13).

Clearly then Hodesh is related to "Yerah", which itself literally means "Moon".

"Hodesh" Means New Moon (Day)

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 1 Samuel
20:5, 18 in which first David says to Yahnathan, and then Yahnathan says to
David "Tomorrow is the New Moon (Hodesh)".

Clearly, in these Verses 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 Yechetzqyah
(Ezekiel) 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.

The Scriptural New Moon is the "First Crescent"

"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.

At the end of the lunar month the Moon is close to the Sun (from the
perspective of an observer on Earth) and eventually reaches the point of
"Conjunction" when it passes between the Sun and the Earth (it is on the same
plane as the Sun and the Earth).

As a result, around the time of Conjunction very little of the Moon's illuminated
surface faces the Earth and it is not visible through the infinitely brighter glare of
the Sun.

After the Moon moves past the Sun it continues towards the opposite side of
the Earth. As it gets farther away from the Sun the percentage of its illuminated
surface facing the Earth increases and one evening shortly after sunset the
Moon is seen anew after being invisible for 1.5-3.5 days. Because the Moon is
seen anew after a period of invisibility the ancients called it a "New Moon" or
"Hodesh" (from Hadash meaning "new").

Crescent New Moon versus Astronomical New Moon

Many people have been led astray by the inaccurate use in modern languages
of the term "New Moon".

Modern astronomers adopted this otherwise unused term, which had always
referred to the first visible sliver, and used it to refer to Conjunction (when the
Moon passes between the Earth and the Sun, at which time it is not visible).

The astronomers soon realized that the inaccurate use of "New Moon" to refer
to Conjunction would lead to confusion so to be more accurate scientists now
distinguish between "Astronomical New Moon" and "Crescent New Moon".

"Astronomical New Moon" means New Moon as the term is used by
astronomers, i.e. Conjunction.

In contrast, "Crescent New Moon" uses the term in the original meaning of the
first visible sliver.

A good English dictionary should reflect both meanings.

For example, the Random House Dictionary of the English Language,
Unabridged Edition defines New Moon as: "The Moon either when in
Conjunction with the Sun or soon after being either invisible [Astronomical New
Moon] or visible [Crescent New Moon] only as a slender crescent." (square
brackets added).

The Supposed Evidence For "Concealed Moon"

Having been confused by the use of the term New Moon in modern astronomy
some people have sought Scriptural support for this incorrect meaning of the
term.

Psalm 81:3 [Heb. 81:4] is usually cited which says:

"Blow on a horn for the Hodesh (New Moon)
On the Keseh (Full Moon) for the Day of our Hag (Feast)."

According to the "Concealed Moon Theory", the term "Keseh" is derived from
the root K.S.Y. meaning "to cover" and thus means "covered Moon" or
"concealed Moon".

According to this interpretation, when the verse says to blow on a horn on the
day of Keseh it actually means "[blow on a horn] on the day of Concealed
Moon".

However, the language does not support this argument for the second half of
the verse also refers to the day of Keseh as "the day of our Feast (Hag)".

In The Scriptures, Feast (Hag) is a technical term which always refers to the
three annual Pilgrimage-Feasts (Matzot, Shavuot, Sukkot; see Exodus Chapters
23 and 34).

Even in the few instances where Hag does not refer to the three Biblical
Pilgrimage-Feasts, it refers to non-Scriptural Pilgrimage-Feasts. For example,
in Judges 21,19 Hag refers to the annual Pilgrimage-Feast held around the
shrine of Shiloh. Also, in Exodus 10,9 Mosheh (Moses) tells Pharaoh that the
Israelites must leave Egypt to celebrate a Hag to YAHWEH (YHWH) in the
desert, which clearly is a Pilgrimage-Feast. It is worth noting that Mosheh
(Moses) says that they have a Hag, meaning they must make a Pilgrimage, in
this case to Mt. Sinai, and thus they must leave Egypt in order to observe the
Hag properly.

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 Scriptural Set Apart Day
of Yom Teruah (Day of Shoutings), which always falls out on New Moon Day.

However, The Scriptures describe Yom Teruah as a Moed (Appointed Time)
and never as a Hag (Pilgrimage-Feast) so Keseh/ Hag can not refer to Yom
Teruah either.

What Does Keseh Really Mean?

It is likely that Keseh is related to the Aramaic word "Kista" and the Assyrian
word "Kuseu" which mean "Full Moon" (see Brown-Driver-Briggs p.490b)
[Hebrew, Aramaic, and Assyrian are all Semitic languages and often share
common roots].

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!

More on "Concealed Moon"

Another point to consider is that there is no actual "Day" of Concealed Moon.

In fact the Moon stays concealed anywhere from 1.5 to 3.5 days in the Middle
East.

It has been proposed that the "Day" of Concealed Moon is actually the Day of
Conjunction (when the Moon passes between the Earth and Sun).

However, it was only 1000 years after Mosheh (Moses) that the Babylonian
astronomers discovered how to calculate the moment of conjunction.

Therefore, the ancient Israelites would have had no way of knowing when the
moment of Conjunction takes place and would not have known on which day to
observe "Concealed Moon Day".

It has been suggested that the ancient Israelites could have looked at the "Old
Moon" and determined the Day of Conjunction by when the Old Moon was no
longer visible in the morning sky.

However, such a method would not work in the Middle East where the so-called
"Concealed Moon" can remain concealed for as many as 3.5 days!

It is in fact common for the Moon to stay concealed for 2.5 days and in such
instances how would the ancient Israelites have known which day was the Day
of Conjunction?

In contrast, the ancient Israelites would have been well aware of the Crescent
New Moon.

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").
The Scriptural New Moon:
Crescent versus Conjunction