it uses the Hebrew calendar which is completely different from modern systems. It is always exactly the same day every year. That Catholics and orthodox sometimes use different days is historically correct usage of the Hebrew calendar. First full moon after the spring equinox is an easy simplification (and likely what the ancients were trying for desbite not having modern astronomy) - but it isn’t correct.
They could have chosen any day but choose dates which the pagens had celebrations. And funny how the resurrection moves every year.
it uses the Hebrew calendar which is completely different from modern systems. It is always exactly the same day every year. That Catholics and orthodox sometimes use different days is historically correct usage of the Hebrew calendar. First full moon after the spring equinox is an easy simplification (and likely what the ancients were trying for desbite not having modern astronomy) - but it isn’t correct.