Peeps--sorry, can't begin to explain what that one has do with Easter Sunday. What makes it even more extraordinary, and impenetrable like with the non sequitur and surreal rituals, is that the date of Easter can vary so widely, so as the holiday escapes one sometimes, and is figured using a complex, alchemy of maths called the Computus. This method not only previsions computer science, algorithms, matrices, all these correcting factors that make modern Western calendars fit to a lunar one are very much like the cosmology of Ptolemy, who, while acknowledging a sun-centered universe would be more straightforward, sought to preserve the appearances of a geocentric model with all sorts of celestial wheels, gears and cogs.
Getting the liturgical dates right in general, counterbalanced with the cycle of the Moon and the observable equinoxes and the odd Leap Year, helped keep annual occcurances meaningful, coinciding with Spring, Mid-Winter, etc., and guard against slippage and calendar migration that would eventually, glacially led to Easter overlapping or falling before Christmas. That holiday would be a bizarre affair to decorate for.