The Passover occurs on the fourteenth day of the first month. It celebrates when the Angel of Death passed over the houses of Israelites during the plague on the firstborn in Egypt. God instructed Moses to put the blood of a year-old male lamb on the doorframe of his house so that his household would be spared. Moses told the rest of the Israelites to do the same. When the Angel of Death came, it passed over all the houses that had blood on the doorway and spared all the first born Israelites. They continued to celebrate this miracle of God at the same time every year; the tenth day of the first month of their year.
Every seven years of Sabbaths or 49 years, there was a Year of Jubilee. On the fiftieth year, the Israelites had to forgive the debt of whoever owed them money, had to release any hired worker, and had to return to their own property, even if they had sold it. They also could not plant crops or harvest anything growing of its own accord. This kept them mindful to the fact that God owns all the property of the world, they merely tend to it, and that god will always provide for them even if they cannot grow anything. God made their crops produce three times as much food so that they would have enough food for the Year of Jubilee.
Day of Atonement:
On the tenth day of the seventh month, the Israelites were required to fast, present an offering by fire, and not do any work. Anyone who did not fast or who worked would be cut off from their people. This day they observed every year and is still celebrated by some Jews and is called Yom Kippur.
Feast of Tabernacles:
The Feast of Tabernacles is celebrated on the fifteenth day of the seventh month and lasts for eight days. The first day and the eighth day were days of rest. On the other days, they took choice fruit and palm fronds or other leafy branches and rejoiced before God. They must also live in booths or temporary houses, just as the Jews did in the wilderness. This celebration was in remembrance of when the children of Israel lived in tents in the desert for forty years.