Why is Easter Sunday always jumping around on the calendar? Why is it so late in April this year?
The Vernal (Spring) Equinox this year was on March 20th.
The first Full Moon following the Vernal Equinox of this year was on April 17th.
That means that day-after-tomorrow, Sunday April 24th, is the first Sunday following the first Full Moon following the Vernal Equinox.
That means that Sunday, April 24th is Easter Sunday for most of the world’s Christians.
Generally speaking, this is how you calculate Easter Sunday:
Vernal Equinox + the following Full Moon + the following Sunday = Easter Sunday.
Given the range of possible dates on which the Full Moon can occur following the Vernal Equinox, this means that the earliest possible Easter Sunday could be March 22nd, and the latest possible date for Easter is April 25th.
If you want to really geek-out about this subject and explore the “generally speaking” qualifier that I mentioned above, and if learning the difference between an “Astronomical Full Moon” and an “Ecclesiastical Full Moon” sounds interesting to you, then go here.