Is it a full moon all around the world within a 24hr time span?
The answer is yes. That’s all you need to know. The religious festival point is well made by ‘I could pink and fluffy’ Easter occurs on the first Sunday after the first full moon following the spring equinox [21 March]. This can be any time between 22 March and 25 April. If we didn’t all see the moon the same, that wouldn’t work.