At the time of Jesus, they would purify before Easter. John 11:
55- And the Jews' passover was nigh at hand: and many went out of the country up to Jerusalem before the passover, to purify themselves.
The lamb had to be prepared, and the people purify on day 10 for Easter on day 14.
Jesus purifies the temple on day 10 for Easter (his Church, his Body).
Jesus gathered all the parties.
Pentecost: offer of wheat harvest (bread).
The Day of Atonement: that is the day of purification, which was the day 10 of the 7th month that is the 1st month of Abib of Easter).
The Tabernacle: presence of God and the law, the temple (Christ) in the middle of the people.
The tabernacle is the 7 days of flat bread after Easter (Leviticus 23. 27 to 32 and 16.29 to 34)

compare with Numbers. 28. and 29.
Jesus gathered all this celebrations where all of God´s people had to congregate and celebrate, with all its sacrifices, annually in Jerusalem; Jesus replaced all by his supper (his sacrifice).
If Judaic Easter, that was the image of the real one, needed so much sacrifice and dedication to remain God´s people, more the real Christian Easter.
Then the Christian Churches of the world with its divisions and confusions, transform such an important act into a ceremony of any day and any way, saying falsely that the apostles had supper every day, from house to house. Acts 2-
46- And they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart, (that was the communion of every day of God´s people, but never the supper).