The Festival of Weeks

26 “ ‘On the day of firstfruits, when you present to the LORD an offering of new grain during the Festival of Weeks, hold a sacred assembly and do no regular work.

Read Numbers 28:26 Using Other Translations

Also in the day of the firstfruits, when ye bring a new meat offering unto the LORD, after your weeks be out, ye shall have an holy convocation; ye shall do no servile work:
"On the day of the firstfruits, when you offer a grain offering of new grain to the LORD at your Feast of Weeks, you shall have a holy convocation. You shall not do any ordinary work,
“At the Festival of Harvest, when you present the first of your new grain to the LORD, you must call an official day for holy assembly, and you may do no ordinary work on that day.