Saturday nights (April 12th) bring about the April full moon, traditionally known as the “pink full moon.” Native Americans, who once occupied the northern and eastern United States, tracked the seasons by giving each full moon a distinctive name that occurred at approximately 29 days’ intervals during the year.
“Pink moon“But the name is pretty deceptive, because it might give the idea that it’s initially on that particular night. full moon It looks like it glows in pinkish or salmon shades. A few years ago, here at Space.com, I was involved Anecdote I was a young boy and a local TV weather caster suggested he went outside and searched for the pink moon. My mother showed it to me and took me faithfully outside.
The “pink” moniker comes from the fact that April is part of the spring season when widely cultivated indigenous flowering plants in the eastern and central parts of Canada and the United States are usually in full bloom. Phlox sublataIt is also called “creeping”, “mountain”, or “mospink” phlox. So the pink reference for the full moon in April.
Rules for dating Easter
This year, the full moon in April has yet another title: Paschal Moon. the Important moon events for two different cultures in that they help set the start of the Hebrew east feast of Passover and the date of the Christian holiday of Easter.
Related: Full Moon Calendar 2025: When you see the next full moon
The nearest new moon Spring Equinox This is the first day of Nisan’s Hebrew Man Month. Then there is the Pesach or Passover in the next full moon, the so-called Pascal Moon, 14 or 15 Nisan.
As for Easter, it falls on the Sunday following the first full moon that occurs after the Vernal (Spring) equinox: The Paschal Moon day. Pashkarumoon is occurring this Saturday (8:22pm EDT) which is why Easter should come the following day, Sunday (April 13th).
But that’s not the case.
In fact, eight days pass after this Pascal full moon before Easter Sunday in 2025 is finally celebrated on April 20th.
But first, we need to quote some “great points” regarding the criteria for specifying Easter dates.
Church hierarchy vs. astronomy
Firstly, according to current church rules, spring equinox – First day of Spring – It will be revised on March 21st worldwide from 2008 to 2101 to 2101, but in reality it will occur by March 20th. In 2038, Equinox will fall on March 20th, with a full moon the following day (Sunday). So astronomically, Easter should fall on March 28th of that year. But in reality, Easter in 2038 will be observed late as long as it could come on April 25th, as mandated by church rules.
Second, Paschal Full Moon’s dating is not based on astronomical calculations, but is taken from the church table. These tables derive the calculation of the month (called Computus paschalis) From elements like Epacts and Golden Number. Therefore, the dates provided by the “Church Month” do not necessarily line up exactly with the actual month!
As a result, as noted by the famous Belgian mathematics astronomer Janmius in his 1997 book, “A bite of mathematical astronomical simplicity” There were 78 cases between 1583 and 2582, where they are celebrated according to the rules of the church, rather than more accurate astronomical data.
Meeus: “Spring Equinox doesn’t always happen on March 21st. There’s a year inevitable as Easter falls on the wrong date, as the PaschalFullMoon doesn’t exactly match the true full moon.”
Related: The full moon that decides Easter
Other Easter Strangeness
Meeus also brings other fascinating facts about Easter dating. for example:
The earliest day Easter can collapse is March 22nd (last was 1818; the next one will be 2285). The latest (as mentioned) is April 25th.
The dates for Easter in March are always “isolated.” In other words, the date for Easter in March always follows the previous (1 year ago) followed by Easter in April (1 year later). In rare cases, there is an isolated April Easter. This last happened in 1990, but it never happens again until 2085.
With us Gregorian calendar10 consecutive Easter Sundays in April could arrive in autumn, but this April Easter string never happened since that calendar was first used in 1582. It was first held in the mid-29th century between 2856 and 2865.
Between 2000 and 7999, the date when Easter collapses most frequently (231 times) is April 19th. However, between 2000 and 2999, the most frequent date when Easter falls is April 16th (43x) rather than April 19th.
So why so much in the second half of 2025?
Now we’re back to the question about why Easter looks late this year. Interestingly, it has nothing to do with the church methodology of dating Pascal Moon or the inaccurate arrangement of the vernal equinox. Here in North America, the Pascal full moon actually occurs (Saturday (April 12th), late afternoon or evening (depending on the timezone).
However, across the Atlantic Ocean for the European crossing (the “old world”), the Pascal full moon occurs After midnightearly Sunday morning (April 13th). This includes the Vatican, which is likely to be prioritized over locations in the Western Hemisphere.
Therefore, the first Sunday after the Pascal Moon in the Old World will come in one week on April 20th. Latest from 2019 and 2030 (both April 21st).
Joe Rao is a New York instructor and guest lecturer Hayden Planetarium. He writes about astronomy Natural History Magazine, Sky and Telescope Other publications.
