Calling the celebration "Easter" or "Passover" matters little. I could call it "PassEaster" and it still wouldn't be one of the days that the Lord commanded us to observe or the days he observed himself.
The germanic languages recognize the same about passover, but have made a play on words about the Sun(Son) RISING (resurrection) in the EASTERly direction.
That's a pretty good justification, but again not biblical.
Eze 8:16 And he brought me into the inner court of the LORD's house, and, behold, at the door of the temple of the LORD, between the porch and the altar, were about five and twenty men, with their backs toward the temple of the LORD, and their faces toward the east; and they worshiped the sun toward the east.
Eze 8:17 Then he said unto me, Hast thou seen this, O son of man? Is it a light thing to the house of Judah that they commit the abominations which they commit here? for they have filled the land with violence, and have returned to provoke me to anger: and, lo, they put the branch to their nose.
I find it interesting that in verses above, the 25 have turned their back to the temple and are worshipping the rising sun. Interesting parallel to today, don't you think?
18.Therefore will I also deal in fury; Mine eye shall not spare, neither will I have pity; and though they cry in Mine ears with a loud voice, yet will I not hear them."
Father cares what we do and how we worship. He chose Passover as The Day His Son would be crucified. Verse 18 tells us how He feels about man's choice of another day, easter, to celebrate the Holiest Day in Christianity.