We know that the feast of tabernacles (booths) identifies with 40 years. But 40 years starting from where?
If we look at the nation of Israel and the historical occasion of their living out the actual events that the feast of tabernacles was designed to bring to remembrance---we find that the 40 years of their dwelling in tents or booths began at the time of their coming out of Egypt.
After a great deliverance, God brought all Israel out of Egypt. He freed them from horrible bondage. It was after their deliverance from captivity that they then began to dwell in booths for a period of 40 years.
The Bible also tells us that the Jubilee year is a feast (also observed in the Hebrew 7th month) that especially identifies with liberty:
Leviticus 25:9 Then shalt thou cause the trumpet of the jubile to sound on the tenth day of the seventh month, in the day of atonement shall ye make the trumpet sound throughout all your land.
10 And ye shall hallow the fiftieth year, and proclaim liberty throughout all the land unto all the inhabitants thereof: it shall be a jubile unto you; and ye shall return every man unto his possession, and ye shall return every man unto his family.
We can find a good deal of similarity between the things the Jubilee represents and the historical occasion of Israel coming out of the land of Egypt and being set free from their bondage.
So, as we look for a place that began the 40 year period of the feast of tabernacles---we find that the year 1994 AD, a Jubilee year, is an excellent year for us to look at. That was the year in which God began to proclaim liberty to all His elect throughout the world.
Again, Israel was set free and immediately began to dwell in booths in the wilderness.
God's elect began to be set free and they also immediately began to dwell in spiritual booths.
What is a spiritual booth?
We'll have to address that question another time.
The important thing now is, that if the pattern for the feast of booths holds true, for those set free (God's elect),the time of dwelling under booths would be 40 years.
1994 AD to 2033 AD = 40 years (inclusive)