Leviticus 23:1-4

And Jehovah spake unto Moses, saying, Speak unto the children of Israel, and say unto them, The set feasts of Jehovah, which ye shall proclaim to be holy convocations, even these are my set feasts. Six days shall work be done: but on the seventh day is a sabbath of solemn rest, a holy convocation; ye shall do no manner of work: it is a sabbath unto Jehovah in all your dwellings. These are the set feasts of Jehovah, even holy convocations, which ye shall proclaim in their appointed season.