Then it will be that all the nations who have come against Jerusalem and survived will go up each year to worship the King, the Lord of Hosts, and to celebrate the Feast of Tabernacles. And it will happen that if any of the families of the earth do not go up to Jerusalem to worship the King, the Lord of Hosts, then there will not be rain for them. If the family of Egypt does not go up and enter in, they shall have no rain. This will be the plague with which the Lord strikes the nations that do not go up to celebrate the Feast of Tabernacles. This will be the punishment of Egypt and the punishment of all the nations who do not go up to celebrate the Feast of Tabernacles. (Zechariah 14:16-19 MEV)
Sukkot, Feast of Tabernacles, will be the most important festival in the millennium. During the millennium, the celebration of Sukkot, Feast of Tabernacles, will become compulsory worldwide.
This day may also be the birthday of the Great King, when He came to earth the first time. It was suggested that He could be born in October, during the Feast of Tabernacles, rightly justifying John 1:14, that the Word tabernacled (dwelt) among us.
And the Word became flesh, and did tabernacle among us, and we beheld his glory, glory as of an only begotten of a father, full of grace and truth. (John 1:14 YLT)