[grey_whiskers]

The date of the Passover determined the date of the Crucifixion. That determined the date of Easter.

Spelled out in sufficient detail yet?

[Just mythoughts]

Actually the spring festivities of quick like a bunny, rolling eggs were celebrated thousands of years before Christ walked this earth in the flesh. It was called Ishtar. Why old king Neb of Babylon had his gate of Ishtar.

What kind of celebration did Christ participate in, lead, or attend on Resurrection day? None.