The Feast of Tabernacles
The Feast of Tabernacles is often cited as a Pinpointed Lunar Sabbath. This is because the days of rest are required on the 15th and 22nd of the seventh month, which coincide with Lunar Sabbath dates.
This page presents the rationale for considering it as a Pinpointed Lunar Sabbath, and discusses several objections.
The Feast of Tabernacles is a seven day festival or Chag, held in the seventh month, from the 15th through the 21st, with an additional feast day on the 22nd of the month. The first day and the eighth day of the Feast are Holy Convocations, during which no work is to be done:
"Speak to the children of Israel, saying: 'The fifteenth day of this seventh month shall be the Feast of Tabernacles for seven days to YHVH. On the first day there shall be a holy convocation. You shall do no customary work on it. For seven days you shall offer an offering made by fire to YHVH. On the eighth day you shall have a holy convocation, and you shall offer an offering made by fire to YHVH. It is a sacred assembly, and you shall do no customary work on it. (Lev 23:34-36)
On the fifteenth day of the seventh month you shall have a holy convocation. You shall do no customary work, and you shall keep a feast to YHVH seven days. (Num 29:12)
On the eighth day you shall have a sacred assembly. You shall do no customary work. (Num 29:35)
Throughout the instructions for the Feast of Tabernacles in Numbers 29:12-39, there are instructions regarding what sacrifices are to be offered that day. However there are no instructions regarding what to do if a Sabbath were to fall on one of those days, much less any mention of a Sabbath day at all between the first and eighth day. Therefore the Sabbath days must fall on the 15th and 22nd, coinciding with the two Holy Convocations.
It is correct that the 15th and the 22nd of the seventh month are Holy Convocations and days of rest. However it's made clear in Lev 23:38 that all of the Holy Days mentioned in Lev 23, and their sacrifices, are to be observed in addition to the weekly Sabbaths:
These are the feasts of YHVH, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto YHVH, a burnt offering, and a meat offering, a sacrifice, and drink offerings, every thing upon his day: Beside the sabbaths of YHVH, and beside your gifts, and beside all your vows, and beside all your freewill offerings, which ye give unto YHVH. (Lev 23:37-38)
Furthermore, the 15th and 22nd days of the seventh month are never referred to as "Sabbaths" in Hebrew. The Hebrew word for Sabbath is shabbath (שַׁבָּת), Strong's Number H7676. The Hebrew word translated as "sabbath" in Lev 23:39 is shabbathon (שַׁבָּתוֹן), Strong's number H7677. Shabbathon is usually translated as "rest", and is sometimes used together with shabbath to describe the Sabbath. For a typical example, consider this verse:
Six days may work be done; but in the seventh is the sabbath (shabbath) of rest (shabbathon), holy to YHVH: whosoever doeth any work in the sabbath (shabbath) day, he shall surely be put to death. (Exo 31:15)
Often times the word shabbath is used alone to describe the Sabbath day, but the word shabbathon is never used alone to describe the Sabbath day. Rather, shabbathon is used alone to describe other Holy Days which are days of rest:
Also in the fifteenth day of the seventh month, when ye have gathered in the fruit of the land, ye shall keep a feast unto YHVH seven days: on the first day shall be a sabbath (shabbathon), and on the eighth day shall be a sabbath (shabbathon). (Lev 23:39)
Therefore, although the first day of the Feast of Tabernacles (the 15th) and the Last Great Day (the 22nd) are days of rest, they are not the same as the weekly Sabbath days.