Leviticus 23:24

23:24 “Tell the Israelites, ‘In the seventh month, on the first day of the month, you must have a complete rest, a memorial announced by loud horn blasts, a holy assembly.

Leviticus 23:36

23:36 For seven days you must present a gift to the Lord. On the eighth day there is to be a holy assembly for you, and you must present a gift to the Lord. It is a solemn assembly day; you must not do any regular work.