What are the "Sabbaths," "New Moons," and "Feasts"?

Question

Several Old Testament passages reference "Sabbaths" (Strongs 07676, shabbath), "New Moons" (Strongs 02320, chodesh), and "Set Feasts" (Strongs 04150, mow‘ed), along with the occasional mention of "feasts" (Strongs 02282, chag) as well (all verses NKJV, emphasis mine):

Behold, I am building a temple for the name of the LORD my God, to dedicate it to Him, to burn before Him sweet incense, for the continual showbread, for the burnt offerings morning and evening, on the Sabbaths [shabbath, 07676], on the New Moons [chodesh, 02320], and on the set feasts [mow‘ed, 04150] of the LORD our God. This is an ordinance forever to Israel. (2 Chronicles 2:4)

The king also appointed a portion of his possessions for the burnt offerings: for the morning and evening burnt offerings, the burnt offerings for the Sabbaths [shabbath, 07676] and the New Moons [chodesh, 02320] and the set feasts [mow‘ed, 04150], as it is written in the Law of the LORD. (2 Chronicles 31:3)

for the showbread, for the regular grain offering, for the regular burnt offering of the Sabbaths [shabbath, 07676], the New Moons [chodesh, 02320], and the set feasts [mow‘ed, 04150]; for the holy things, for the sin offerings to make atonement for Israel, and all the work of the house of our God. (Nehemiah 10:33)

Then it shall be the prince’s part to give burnt offerings, grain offerings, and drink offerings, at the feasts [chag, 02282], the New Moons [chodesh, 02320], the Sabbaths [shabbath, 07676], and at all the appointed seasons [mow‘ed, 04150] of the house of Israel. He shall prepare the sin offering, the grain offering, the burnt offering, and the peace offerings to make atonement for the house of Israel. (Ezekiel 45:17)

I will also cause all her mirth to cease, Her feast days [chag, 02282], Her New Moons [chodesh, 02320], Her Sabbaths [shabbath, 07676]—All her appointed feasts [mow‘ed, 04150]. (Hosea 2:11)

What do each of the three (or four) terms mean in these passages?

Answer 1

What are the "Sabbaths," "New Moons," and "Feasts"?

To start, let's look at the context of 2 Chronicles 2:4. This was King Solomon talking to Hiram, the king of Tyre, about his wanting to build the First Temple as a permanent replacement for the tabernacle. So the everything that is mentioned is in reference to the worship of Jehovah God as outlined in the Law covenant. As the OP mentions, the original Hebrew words are consistent throughout the scriptures referenced in the question.

Sabbaths
This of course is in reference to the Sabbath(s) that the nation of Israel was to observe:

but the seventh day is a sabbath to Jehovah your God. You must not do any work, neither you nor your son nor your daughter nor your slave man nor your slave girl nor your domestic animal nor your foreign resident who is inside your settlements.–Exodus 20:10

However, on the Sabbath day, the offering should be two sound year-old male lambs and two tenths of an eʹphah measure of fine flour mixed with oil as a grain offering, together with its drink offering.–Numbers 28:9

New Moons
The new moon marked the first day of the month in the Jewish calendar. This day was a day of celebration and of offering sacrifices. (Source: New World Translation Glossary)

At the start of each month you will present as a burnt offering to Jehovah two young bulls, one ram, and seven sound male lambs each a year old.–Numbers 28:11

Set Feasts
Set Feasts, or festival seasons, refers to the three times a year in which men were to go to Jerusalem:

Three times a year, all your males should appear before Jehovah your God in the place that he chooses: at the Festival of Unleavened Bread, the Festival of Weeks, and the Festival of Booths, and none of them should appear before Jehovah empty-handed.–Deuteronomy 16:16

The "Set Feasts" (H4150, mow‘ed) and "feasts" (H2282, chag) do have slightly different meanings. Under the subheading "The Three Great Festivals", the topic "Festival" in the Insight on the Scriptures gives us the distinction:

The three primary “seasonal festivals,” sometimes called pilgrimage festivals because of the assembling of all males at Jerusalem, occurred at appointed times and were designated by the Hebrew word moh·ʽedhʹ. (Le 23:2, 4) But the word often used when referring exclusively to the three great festivals is chagh, which connotes not only a periodic occurrence but also a time of great rejoicing.

We see that mow‘ed is focused more on the timing of the festival in contrast to chag which focuses on the three great festivals of Deuteronomy 16:16.

[All scripture quotations from the New World Translation of the Holy Scriptures (Study Edition)]

Answer 2

The OP asks about four terms in the Hebrew OT as follows:

1. Sabbath שַׁבָּת

This word refers to one of the following ideas:

• The weekly Sabbath, Ex 16:23, 25, 26, 29, 20:8, 10, 11, 31:15, 16, 35:2, 3, etc. (This the most common.)
• The week (7 days), Lev 23:15, 25:8 (Only these.)
• The Sabbatical year, Lev 25:2, 4, 26:34, 43, 2 Chron 26:21 (Only these)
• The Day of Atonement, Lev 16:31, 23:32 (Only here)
• "Sabbaths" (plural) appears to refer to all of the above collectively, Ex 31:13, Lev 26:34, 19:30, Eze 20:12, 20.

2. "New Moons"

These "New Moon" feasts/festivities are never defined in the Torah but appear to have the custom from early times, Num 10:10, 28:11, 14, 29:6, 1 Sam 20:5, 18, 24, 27, 34, 2 Kings 4:23, 1 Chron 23:31, etc.

3. Set Feast מוֹעֵד (moed)

The set feasts are clearly defined in the Torah:

• Ex 23:14 - Three times a year you are to celebrate a feast to Me.
• Ex 23:17 - Three times a year all your males are to appear before the Lord GOD.
• Ex 34:23, 24 - Three times a year all your males are to appear before the Lord GOD, the God of Israel. For I will drive out the nations before you and enlarge your borders, and no one will covet your land when you go up three times a year to appear before the LORD your God.
• Deut 16:16 - Three times a year all your men are to appear before the LORD your God in the place He will choose: at [1] the Feast of Unleavened Bread, [2] the Feast of Weeks, and the [3] Feast of Tabernacles. No one should appear before the LORD empty-handed.
• 1 Kings 9:25 - Three times a year Solomon offered burnt offerings and peace offerings on the altar he had built for the LORD, burning incense with them before the LORD. So he completed the temple.
• 2 Chron 8:13 - He [Solomon] observed the daily requirement for offerings according to the commandment of Moses for Sabbaths, New Moons, and the three annual appointed feasts—the Feast of Unleavened Bread,c the Feast of Weeks, and the Feast of Tabernacles.

The three annual set-feats were (see Ex 23, Lev 23, Deut 16 etc): (a) Passover/unleavened bread (b) Feasts of weeks or Pentecost (c) Feast of Trumpets, Atonement & Tabernacles

4. Feast חַג (chag)

This word apparently is used almost synonymously with the above, Ex 12:14, 13:6, 23:15, 16, 18, 34:18, 22, 25, Lev 23:6, 34, 39, 41, Num 29:12, Deut 16:10, etc.

However, this word is occasionally used of a sacred (but false) feast more generally such as the golden calf (Ex 32:5, 19) and the imitation feast of Jeroboam (1 Kings 12:32, 33).

Answer 3

If יָ֖רֵחַ Yareach (Moon) is חֹ֖שֶׁךְ choshek (darkness), then it is a new חֹדֶשׁ Chodesh (Month).

Moedim מֽוֹעֲדִ֑ים (Appointed Times) are marked by the lunar cycle of Yareach set by Shemesh, as stated in Psalm 104:19.

Keseh כֶּ֗סֶה (Full Moon) = 15th of each Chodesh, when light of Shemesh "covers" Yareach, as stated in Psalm 81:4.

Answer 4

To visualize the 'new moon days' the 'seventh days' and 'the feast days' in their chronologically correct order, supported by 17 chronological evidences from scripture alone: The Qodesh Calendar, a KJV discovery 2012. http://freepdfhosting.com/2518d2fd56.pdf