Leviticus 22.26–23.44:
God told Moses that when an ox or a sheep or a goat is born, it was to stay seven days with its mother, and from the eighth day on it could be offered to God. No animal was to be slaughtered on the same day as its young. A thanksgiving offering was to be eaten on the same day that it was sacrificed, and the Israelites were not to leave any of it until the morning.
God told Moses to instruct the Israelites to proclaim the following sacred occasions:
Numbers 29.12–16:
God told Moses to command the Israelites that on the fifteenth day of the seventh month, they were to observe a sacred occasion and not work at their occupations. For seven days they were to observe a festival of the Lord. They were present a burnt offering of thirteen bulls, two rams, and fourteen lambs without blemish. They were to accompany those sacrifices with meal offerings of choice flour mixed with oil. And they were to bring a goat for a sin offering, in addition to the regular offerings.