There are a few reasons Feast of Tabernacles could be the time of the rapture.  The Mount of Transfiguration took place during this feast where Jesus appeared in his glory with Moses and Elijah.  Peter even offered to build a booth for each of them in honor of the feast.  This Mount of Transfiguration (Matthew 17) seems to be a picture of the rapture as Moses and Elijah are thought to be the two witnesses who have a ministry during the 7 year tribulation.

In Leviticus 23:39 the first and last days of Tabernacles is referred to as a Sabbath rest.  Paul also refers to the rapture as a “rest for the people of God” (Hebrews 4).  All citizens of Israel are to live in booths during this week to celebrate being brought out of Egypt.  Interesting that currently, all Israel is under lockdown now because of coronavirus; perhaps there is a correlation here.  The seventh day of Tabernacles is called Hoshanah Rabbah;  “The Zohar says that while the judgment of the new year is sealed on Yom Kippur, it is not “delivered” until the end of Sukkot, so the judgments begin after that.”