Shemini Atzeret follows the seven days of Sukkot and is considered the Eighth Day Assembly. This is a time to gather to worship the Lord for one more day. This is not considered a Holy Day in the Feasts found in Leviticus 23, but it is a day to ponder on the love of the Lord.
** This is a Sabbath unto the Lord: “Do no regular work.” Lev. 23:36.