Numbers 29:1

On the first day of the seventh month you shall have a holy convocation . You shall not do any ordinary work . It is a day for you to blow the trumpets ,

“‘On the first day of the seventh month hold a sacred assembly and do no regular work. It is a day for you to sound the trumpets.

And in the seventh month, on the first day of the month, ye shall have an holy convocation; ye shall do no servile work : it is a day of blowing the trumpets unto you.