Atzeret

[debi b]

The Hebrew word atzeret is often translated “solemn assembly” “convocation” etc. It comes from a root that means to restrain, hold back, withhold, to stop. Why is the last day of Pesach atzeret, a day after Sukkot atzeret, and no association with Shavuot? (Margolin, Metsudah and Stone are different translations - the first one is from Koren Publishers)

Pesach
Devarim/Deut 16: 8
Six days you shall eat unleavened bread; and on the seventh day shall be a solemn assembly to Adonai your Elohim; you shall do no work in it.
Margolin: …and on the seventh day [will be] a day of restriction…
Metsudah: …and on the seventh day is one of withdrawl…
Stone: ….the seventh day shall be an assembly to HASHEM…

Shemini Atzeret
Vayikra/Lev 23:36
Seven days you shall offer an offering made by fire to Adonai; on the eighth day shall be a holy gathering to you; and you shall offer an offering made by fire to Adonai; it is a solemn assembly; and you shall do no labor in it.
Margolin: …it is [G-d’s] Retainment [of Israel]…
Metsudah: …it is a day of convocation for you…
Stone:…it is an assembly…

Bamidbar/Numbers 29: 35
On the eighth day you shall have a solemn assembly; you shall do no labor in it;
Margolin: The eighth day shall be a [day of] restriction…
Metsudah: The eighth day shall be a [day of] restraint…
Stone: The eighth day shall be a restriction for you…

[visionary]

Feast of Tabernacles

33 The LORD said to Moses, 34 "Say to the Israelites: 'On the fifteenth day of the seventh month the LORD's Feast of Tabernacles begins, and it lasts for seven days. 35 The first day is a sacred assembly; do no regular work. 36 For seven days present offerings made to the LORD by fire, and on the eighth day hold a sacred assembly and present an offering made to the LORD by fire. It is the closing assembly; do no regular work.(KJV)

Since it is the last of the Fall Feasts and when you look at them from the spring type to fall type fulfillments, it is the last ceremonial feast to be fulfilled. I think that makes it a very appropriate ending to the fulfillment of spiritual feasts.

[visionary]

The Feast of Tabernacles is known as the Final fall harvest of the Land, and on the eighth day it will be the final harvest of souls with the Lord’s Return.

[debi b]

Why is the last day of Pesach atzeret, a day after Sukkot atzeret, and no association with Shavuot?

:)