Aligned Easters
March 31, 2025 at 7:19 PM by Dr. Drang
I was reading a news article today about Trump’s hope to get a ceasefire in Ukraine arranged by April 20 because it’s Easter. I thought, “Wait, that’s our Easter, but is it also Ukraine’s Easter?” Based on the Ukrainian neighborhoods in Chicago, I assumed most of Ukraine would celebrate Orthodox Easter, not the Easter set by the Western Church.
It turns out that this year they’re on the same day, something that happens more frequently than I would’ve guessed, but still less often than not.
Here are the dates of both Easters for the 50-year period starting in 2001:
| Year | Western | Orthodox | Same? | Wks apart |
|---|---|---|---|---|
| 2001 | Apr 15 | Apr 15 | Yes | 0 |
| 2002 | Mar 31 | May 05 | No | 5 |
| 2003 | Apr 20 | Apr 27 | No | 1 |
| 2004 | Apr 11 | Apr 11 | Yes | 0 |
| 2005 | Mar 27 | May 01 | No | 5 |
| 2006 | Apr 16 | Apr 23 | No | 1 |
| 2007 | Apr 08 | Apr 08 | Yes | 0 |
| 2008 | Mar 23 | Apr 27 | No | 5 |
| 2009 | Apr 12 | Apr 19 | No | 1 |
| 2010 | Apr 04 | Apr 04 | Yes | 0 |
| 2011 | Apr 24 | Apr 24 | Yes | 0 |
| 2012 | Apr 08 | Apr 15 | No | 1 |
| 2013 | Mar 31 | May 05 | No | 5 |
| 2014 | Apr 20 | Apr 20 | Yes | 0 |
| 2015 | Apr 05 | Apr 12 | No | 1 |
| 2016 | Mar 27 | May 01 | No | 5 |
| 2017 | Apr 16 | Apr 16 | Yes | 0 |
| 2018 | Apr 01 | Apr 08 | No | 1 |
| 2019 | Apr 21 | Apr 28 | No | 1 |
| 2020 | Apr 12 | Apr 19 | No | 1 |
| 2021 | Apr 04 | May 02 | No | 4 |
| 2022 | Apr 17 | Apr 24 | No | 1 |
| 2023 | Apr 09 | Apr 16 | No | 1 |
| 2024 | Mar 31 | May 05 | No | 5 |
| 2025 | Apr 20 | Apr 20 | Yes | 0 |
| 2026 | Apr 05 | Apr 12 | No | 1 |
| 2027 | Mar 28 | May 02 | No | 5 |
| 2028 | Apr 16 | Apr 16 | Yes | 0 |
| 2029 | Apr 01 | Apr 08 | No | 1 |
| 2030 | Apr 21 | Apr 28 | No | 1 |
| 2031 | Apr 13 | Apr 13 | Yes | 0 |
| 2032 | Mar 28 | May 02 | No | 5 |
| 2033 | Apr 17 | Apr 24 | No | 1 |
| 2034 | Apr 09 | Apr 09 | Yes | 0 |
| 2035 | Mar 25 | Apr 29 | No | 5 |
| 2036 | Apr 13 | Apr 20 | No | 1 |
| 2037 | Apr 05 | Apr 05 | Yes | 0 |
| 2038 | Apr 25 | Apr 25 | Yes | 0 |
| 2039 | Apr 10 | Apr 17 | No | 1 |
| 2040 | Apr 01 | May 06 | No | 5 |
| 2041 | Apr 21 | Apr 21 | Yes | 0 |
| 2042 | Apr 06 | Apr 13 | No | 1 |
| 2043 | Mar 29 | May 03 | No | 5 |
| 2044 | Apr 17 | Apr 24 | No | 1 |
| 2045 | Apr 09 | Apr 09 | Yes | 0 |
| 2046 | Mar 25 | Apr 29 | No | 5 |
| 2047 | Apr 14 | Apr 21 | No | 1 |
| 2048 | Apr 05 | Apr 05 | Yes | 0 |
| 2049 | Apr 18 | Apr 25 | No | 1 |
| 2050 | Apr 10 | Apr 17 | No | 1 |
There are 16 years in which the dates match. The two Easters are typically either 1 or 5 weeks apart, with the Orthodox Easter coming later. This year is the first alignment since 2017, which is the longest stretch of Nos over this period. I have no idea whether this period is in any sense typical. The calculation of Easter is complicated and the formulas don’t have any obvious period.
Here’s the Python code I used (in a Jupyter console session) to build the table:
from dateutil.easter import *
for y in range(2001, 2051):
west = easter(y, EASTER_WESTERN)
east = easter(y, EASTER_ORTHODOX)
diff = (east - west).days // 7
print(f'| {y} | {west.strftime('%b %d')} | {east.strftime('%b %d')} | {"Yes" if diff==0 else " No"} | {diff} |')The pipe characters in Line 7 are part of the MultiMarkdown table format.
The dateutil module has an easter submodule, which is perfect for making this comparison. The EASTER_ORTHODOX flag gives the date for Orthodox Easter in the Gregorian calendar. There’s also an EASTER_JULIAN flag, which gives Orthodox Easter in the Julian calendar. This is historically and culturally useful but not helpful when you want to compare it with a Gregorian date.