Easter or Passover is also a celebration for hundreds millions humans all over the world.
It is mainly celebrated by Aramaics, Christians, Hebrews and Romans. Other internet sources have covered thoroughly the rituals and customs of Easter or Passover.
The only proposal that has to be applied is the common date of celebration by all or most of the tribes who accept Easter or Passover.There are various contradictions among leaders of the churches that celebrate the custom and tradition of Easter or Passover. I am favour of unification actions and processes instead of schisms and heresy.
The First Ecumenical Conference of Nikaia (325 a.c.) decided that Easter has to be celebrated the First Sunday after the Full Moon of the equinox. Even if there are different opinions about the exact date of Easter, the aforementioned has to prevail.
The Fundamental reason is that you cannot hide the moon from the sky or the universe.
Therefore, astronomers can observe the sky and when they report that there is a Full Moon of the equinox, we celebrate the First Sunday as Easter.