THE EASTER DATE................ [Se preferir, veja a página em Português com mais detalhes]

GaussDelambre

Thanks to the German Mathematician Karl Friedrich Gauss (1777-1855), the French Astronomer Jean Baptiste Joseph Delambre (1749-1822) and others, we have the definitive algorithm to find the Easter date, any year, from 1 AD to infinity.

Get the Easter Sunday from the next formulae, or run the program below, introducing Year (from 1 AD to infinity). See, also, the respective Carnival Tuesday (47 days before Easter) and Corpus Christi Thursday (60 days after Easter):

Year The EASTER Sunday
CARNIVAL Tuesday.
C.CHRISTI Thursday

Note: If you compare this calendar with the one in Microsoft/Office/Excel, you will find a difference in year 1900. This is a problem in Excel, that incorrectly considers 1900 a leap year. Any attempt to calculate former dates (before 1900 March 1st), starting from Excel calendar, will result 1 day mistake.

Gregorian Calendar (1583...)
Make
A = Mod(Year ÷ 19)
B = Int(Year ÷ 100)
C = Mod(Year ÷ 100)
D = Int(B ÷ 4)
E = Mod(B ÷ 4)
F = Int[(B + 8) ÷ 25]
G = Int[(B - F + 1) ÷ 3]
H = Mod[(19xA + B - D - G + 15) ÷ 30]
I = Int(C ÷ 4)
K = Mod(C ÷ 4)
L = Mod[(32 + 2xE + 2xI - H - K) ÷ 7]
M = Int[(A + 11xH + 22xL) ÷ 451]
P = Int[(H + L - 7xM + 114) ÷ 31]
Q = Mod[(H + L - 7xM + 114) ÷ 31]
Easter date will be on P month, Q+1 day
Julian Calendar (...1582)
Make
A = Mod(Year ÷ 4)
B = Mod(Year ÷ 7)
C = Mod(Year ÷ 19)
D = Mod[(19xC + 15) ÷ 30]
E = Mod[(2xA + 4xB - D + 34) ÷ 7]
F = Int[(D + E + 114) ÷ 31]
G = Mod[(D + E + 114) ÷ 31]
Easter date will be on F month, G+1 day

Mod = Remainder
Int = Integer

If you prefer, print and assemble a pocket liturgical disk (2000 to 2099 years), going to the drawing page:

Liturgical Disk

Some explanations, from Jean Meeus in "Astronomical Algorithms" excellent book:

Easter is the first Sunday after the Full Moon that happens on or next after the Spring equinox. Good Friday happens two days before Easter. Actually, the rules for finding the Easter date were fixed long ago by the Christian clergy. For the purposes of these rules, the Full Moon is reckoned according to an ecclesiastical computation and is not the real, astronomical Full Moon. Likewise, the equinox is always assumed to fall on March 21; actually, it can occur a day or two sooner. (The formulae above are according with the ecclesiastical rules)

In 1967, for instance, the Full Moon was on March 26 (3h21m GMT). The first Sunday after March 26 was April 2. Nevertheless, Easter Sunday was March 26.

During the period 1900-2100, the purely astronomical rule yields another date for Easter Sunday than the ecclesiastical rule for the following years: 1900, 1903, 1923, 1924, 1927, 1943, 1954, 1962, 1967, 1974, 1981, 2038, 2049, 2069, 2076, 2089, 2095 and 2096.

A period of 5 700 000 years is required for the cyclical recurrence of the Gregorian Easter dates. It has been found that the most frequent Gregorian Easter date is April 19.

The date of the Julian Easter has a periodicity of 532 years. For instance, we find April 12 for the years 179, 711 and 1243.

The extreme dates of Easter are March 22 and April 25.

Look at the ready reckoner below, for 1900 to 2099 years:


19.. YEAR       EASTER CARNIVAL C.CHRISTI
-----------------------------------------
00-06-79-90     Apr 15  Feb 27   Jun 14
01-85           Apr  7  Feb 19   Jun  6
02-75-86-97     Mar 30  Feb 11   May 29
03-14-25-98     Apr 12  Feb 24   Jun 11
04-88           Apr  3  Feb 16   Jun  2
05-16           Apr 23  Mar  7   Jun 22
07-18-29-91     Mar 31  Feb 12   May 30
08-81-87-92     Apr 19  Mar  3   Jun 18
09-71-82-93     Apr 11  Feb 23   Jun 10
10-21           Mar 27  Feb  8   May 26
11-22-33-95     Apr 16  Feb 28   Jun 15
12-96           Apr  7  Feb 20   Jun  6
13              Mar 23  Feb  4   May 22
15-26-99        Apr  4  Feb 16   Jun  3
17              Apr  8  Feb 20   Jun  7
19-24-30        Apr 20  Mar  4   Jun 19
20              Apr  4  Feb 17   Jun  3
23-34-45        Apr  1  Feb 13   May 31
27-38-49-60     Apr 17  Mar  1   Jun 16
28              Apr  8  Feb 21   Jun  7
31-42-53        Apr  5  Feb 17   Jun  4
32              Mar 27  Feb  9   May 26
35-46-57        Apr 21  Mar  5   Jun 20
36              Apr 12  Feb 25   Jun 11
37              Mar 28  Feb  9   May 27
39-50           Apr  9  Feb 21   Jun  8
40              Mar 24  Feb  6   May 23
41              Apr 13  Feb 25   Jun 12
43              Apr 25  Mar  9   Jun 24
44              Apr  9  Feb 22   Jun  8
47-58-69        Apr  6  Feb 18   Jun  5
48              Mar 28  Feb 10   May 27
51              Mar 25  Feb  6   May 24
52              Apr 13  Feb 26   Jun 12
54-65-76        Apr 18  Mar  2   Jun 17
55-66-77        Apr 10  Feb 22   Jun  9
56              Apr  1  Feb 14   May 31
59-70           Mar 29  Feb 10   May 28
61              Apr  2  Feb 14   Jun  1
62-73-84        Apr 22  Mar  6   Jun 21
63              Apr 14  Feb 26   Jun 13
64              Mar 29  Feb 11   May 28
67-78-89        Mar 26  Feb  7   May 25
68              Apr 14  Feb 27   Jun 13
72              Apr  2  Feb 15   Jun  1
74              Apr 14  Feb 26   Jun 13
80              Apr  6  Feb 19   Jun  5
83-94           Apr  3  Feb 15   Jun  2

20.. YEAR       EASTER CARNIVAL C.CHRISTI 
-----------------------------------------
00-79           Apr 23  Mar  7   Jun 22   
01-63-74-85     Apr 15  Feb 27   Jun 14   
02-13-86-97     Mar 31  Feb 12   May 30   
03-14-25-87-98  Apr 20  Mar  4   Jun 19   
04-88           Apr 11  Feb 24   Jun 10   
05              Mar 27  Feb  8   May 26   
06-17-90        Apr 16  Feb 28   Jun 15   
07-91           Apr  8  Feb 20   Jun  7   
08              Mar 23  Feb  5   May 22  
09-93-99        Apr 12  Feb 24   Jun 11   
10-21-83-94     Apr  4  Feb 16   Jun  3   
11-95           Apr 24  Mar  8   Jun 23   
12              Apr  8  Feb 21   Jun  7   
15-26-37        Apr  5  Feb 17   Jun  4   
16              Mar 27  Feb  9   May 26   
18-29           Apr  1  Feb 13   May 31  
19-30-41-52     Apr 21  Mar  5   Jun 20   
20              Apr 12  Feb 25   Jun 11   
22-33-44        Apr 17  Mar  1   Jun 16  
23-34-45        Apr  9  Feb 21   Jun  8   
24              Mar 31  Feb 13   May 30   
27              Mar 28  Feb  9   May 27   
28              Apr 16  Feb 29   Jun 15   
31              Apr 13  Feb 25   Jun 12   
32              Mar 28  Feb 10   May 27  
35-46           Mar 25  Feb  6   May 24
36              Apr 13  Feb 26   Jun 12
38              Apr 25  Mar  9   Jun 24
39-50-61        Apr 10  Feb 22   Jun  9
40              Apr  1  Feb 14   May 31
42-53           Apr  6  Feb 18   Jun  5
43-54-65        Mar 29  Feb 10   May 28
47-58-69        Apr 14  Feb 26   Jun 13
48              Apr  5  Feb 18   Jun  4
49-55-60        Apr 18  Mar  2   Jun 17
51              Apr  2  Feb 14   Jun  1
56              Apr  2  Feb 15   Jun  1
57-68           Apr 22  Mar  6   Jun 21
59-70-81        Mar 30  Feb 11   May 29
62-73           Mar 26  Feb  7   May 25
64              Apr  6  Feb 19   Jun  5
66-77           Apr 11  Feb 23   Jun 10
67-78-89        Apr  3  Feb 15   Jun  2
71-76-82        Apr 19  Mar  3   Jun 18
72              Apr 10  Feb 23   Jun  9
75              Apr  7  Feb 19   Jun  6
80              Apr  7  Feb 20   Jun  6
84              Mar 26  Feb  8   May 25
92              Mar 30  Feb 12   May 29
96              Apr 15  Feb 28   Jun 14

EASTER    = Sunday 
CARNIVAL  = Tuesday (47 days before Easter) 
C.CHRISTI = Thursday (60 days after Easter)
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© 01/01/2000 Atualizada em 06/09/2015