Jesus is the Lamb of God
The Lord Jesus Christ celebrated this holiday and was crucified during the passover season. So in reality, his resurrection should be celebrated during this time as well.
Jesus is the passover Lamb of God who died to take away our sin, rose from the dead and is ALIVE today!
5 And entering into the sepulchre, they saw a young man sitting on the right side, clothed in a long white garment; and they were affrighted.
6 And he saith unto them, Be not affrighted: Ye seek Jesus of Nazareth, which was crucified: he is risen; he is not here: behold the place where they laid him.
7 But go your way, tell his disciples and Peter that he goeth before you into Galilee: there shall ye see him, as he said unto you.John 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world. John 1:28-30 (in Context) John 1 (Whole Chapter)
John 1:36And looking upon Jesus as he walked, he saith, Behold the Lamb of God! John 1:35-37 (in Context) John 1 (Whole Chapter)
Read about the first passover in Exodus 12 and read all the places were the word 'passover' is in the scriptures.
And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him:
Revelation 22:2-4 (in Context) Revelation 22 (Whole Chapter)