The LORD said to Moses,
"Give the Israelites instructions regarding the LORD's appointed festivals, the days when all of you will be summoned to worship me.
You may work for six days each week, but on the seventh day all work must come to a complete stop. It is the LORD's Sabbath day of complete rest, a holy day to assemble for worship. It must be observed wherever you live.
In addition to the Sabbath, the LORD has established festivals, the holy occasions to be observed at the proper time each year."
"First comes the LORD's Passover, which begins at twilight on its appointed day in early spring.
References for Leviticus 23:5
Then the day after the Passover celebration, the Festival of Unleavened Bread begins. This festival to the LORD continues for seven days, and during that time all the bread you eat must be made without yeast.
References for Leviticus 23:6