Leviticus 23:33-36

The LORD said to Moses, “Say to the Israelites: ‘On the fifteenth day of the seventh month the LORD’s Festival of Tabernacles begins, and it lasts for seven days. The first day is a sacred assembly; do no regular work. For seven days present food offerings to the LORD, and on the eighth day hold a sacred assembly and present a food offering to the LORD. It is the closing special assembly; do no regular work.