Deuteronomy 16:1, 10, 13

“In honor of the LORD your God, celebrate the Passover each year in the early spring, in the month of Abib, for that was the month in which the LORD your God brought you out of Egypt by night.

Then celebrate the Festival of Harvest to honor the LORD your God. Bring him a voluntary offering in proportion to the blessings you have received from him.

“You must observe the Festival of Shelters for seven days at the end of the harvest season, after the grain has been threshed and the grapes have been pressed.