## Calculate the Date of Easter Sunday

**This Document Explains:**

- The complete procedure for calculating Easter Sunday dates for all years 326 to 4099 A.D.
- How to work out Easter Sunday dates quickly and easily for yourself.
- The Easter Method Calculation.
- The way in which Easter dating methods evolved, and provides
- Lists of Easter Sunday dates for the last 300 and next 300 years.

### List of Easter Sunday Dates

This year Easter Sunday is on** 27th March 2016**

### Easter Dating Method

- How is Easter Sunday Date Determined?
- Finding Easter Sunday Dates with a Calculator
- Finding Orthodox Easter Sunday Dates with a Calculator
- Easter Algorithm for a Computer Program

*This simplified Easter Dating Method was produced by Ronald W. Mallen Research by Ronald W. Mallen, Adelaide, Australia Programming algorithm by Greg Mallen*

List of Easter Sunday Dates 1700-1799 |
---|

11th April 1700 1st April 1725 29th March 1750 16th April 1775 27th March 1701 21st April 1726 11th April 1751 7th April 1776 16th April 1702 13th April 1727 2nd April 1752 30th March 1777 8th April 1703 28th March 1728 22nd April 1753 19th April 1778 23rd March 1704 17th April 1729 14th April 1754 4th April 1779 12th April 1705 9th April 1730 30th March 1755 26th March 1780 4th April 1706 25th March 1731 18th April 1756 15th April 1781 24th April 1707 13th April 1732 10th April 1757 31st March 1782 8th April 1708 5th April 1733 26th March 1758 20th April 1783 31st March 1709 25th April 1734 15th April 1759 11th April 1784 20th April 1710 10th April 1735 6th April 1760 27th March 1785 5th April 1711 1st April 1736 22nd March 1761 16th April 1786 27th March 1712 21st April 1737 11th April 1762 8th April 1787 16th April 1713 6th April 1738 3rd April 1763 23rd March 1788 1st April 1714 29th March 1739 22nd April 1764 12th April 1789 21st April 1715 17th April 1740 7th April 1765 4th April 1790 12th April 1716 2nd April 1741 30th March 1766 24th April 1791 28th March 1717 25th March 1742 19th April 1767 8th April 1792 17th April 1718 14th April 1743 3rd April 1768 31st March 1793 9th April 1719 5th April 1744 26th March 1769 20th April 1794 31st March 1720 18th April 1745 15th April 1770 5th April 1795 13th April 1721 10th April 1746 31st March 1771 27th March 1796 5th April 1722 2nd April 1747 19th April 1772 16th April 1797 28th March 1723 14th April 1748 11th April 1773 8th April 1798 16th April 1724 6th April 1749 3rd April 1774 24th March 1799

List of Easter Sunday Dates 1800-1899 |
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13th April 1800 3rd April 1825 31st March 1850 28th March 1875 5th April 1801 26th March 1826 20th April 1851 16th April 1876 18th April 1802 15th April 1827 11th April 1852 1st April 1877 10th April 1803 6th April 1828 27th March 1853 21st April 1878 1st April 1804 19th April 1829 16th April 1854 13th April 1879 14th April 1805 11th April 1830 8th April 1855 28th March 1880 6th April 1806 3rd April 1831 23rd March 1856 17th April 1881 29th March 1807 22nd April 1832 12th April 1857 9th April 1882 17th April 1808 7th April 1833 4th April 1858 25th March 1883 2nd April 1809 30th March 1834 24th April 1859 13th April 1884 22nd April 1810 19th April 1835 8th April 1860 5th April 1885 14th April 1811 3rd April 1836 31st March 1861 25th April 1886 29th March 1812 26th March 1837 20th April 1862 10th April 1887 18th April 1813 15th April 1838 5th April 1863 1st April 1888 10th April 1814 31st March 1839 27th March 1864 21st April 1889 26th March 1815 19th April 1840 16th April 1865 6th April 1890 14th April 1816 11th April 1841 1st April 1866 29th March 1891 6th April 1817 27th March 1842 21st April 1867 17th April 1892 22nd March 1818 16th April 1843 12th April 1868 2nd April 1893 11th April 1819 7th April 1844 28th March 1869 25th March 1894 2nd April 1820 23rd March 1845 17th April 1870 14th April 1895 22nd April 1821 12th April 1846 9th April 1871 5th April 1896 7th April 1822 4th April 1847 31st March 1872 18th April 1897 30th March 1823 23rd April 1848 13th April 1873 10th April 1898 18th April 1824 8th April 1849 5th April 1874 2nd April 1899

List of Easter Sunday Dates 1900-1999 |
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15th April 1900 12th April 1925 9th April 1950 30th March 1975 7th April 1901 4th April 1926 25th March 1951 18th April 1976 30th March 1902 17th April 1927 13th April 1952 10th April 1977 12th April 1903 8th April 1928 5th April 1953 26th March 1978 3rd April 1904 31st March 1929 18th April 1954 15th April 1979 23rd April 1905 20th April 1930 10th April 1955 6th April 1980 15th April 1906 5th April 1931 1st April 1956 19th April 1981 31st March 1907 27th March 1932 21st April 1957 11th April 1982 19th April 1908 16th April 1933 6th April 1958 3rd April 1983 11th April 1909 1st April 1934 29th March 1959 22nd April 1984 27th March 1910 21st April 1935 17th April 1960 7th April 1985 16th April 1911 12th April 1936 2nd April 1961 30th March 1986 7th April 1912 28th March 1937 22nd April 1962 19th April 1987 23rd March 1913 17th April 1938 14th April 1963 3rd April 1988 12th April 1914 9th April 1939 29th March 1964 26th March 1989 4th April 1915 24th March 1940 18th April 1965 15th April 1990 23rd April 1916 13th April 1941 10th April 1966 31st March 1991 8th April 1917 5th April 1942 26th March 1967 19th April 1992 31st March 1918 25th April 1943 14th April 1968 11th April 1993 20th April 1919 9th April 1944 6th April 1969 3rd April 1994 4th April 1920 1st April 1945 29th March 1970 16th April 1995 27th March 1921 21st April 1946 11th April 1971 7th April 1996 16th April 1922 6th April 1947 2nd April 1972 30th March 1997 1st April 1923 28th March 1948 22nd April 1973 12th April 1998 20th April 1924 17th April 1949 14th April 1974 4th April 1999

List of Easter Sunday Dates 2000-2099 |
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23rd April 2000 20th April 2025 10th April 2050 7th April 2075 15th April 2001 5th April 2026 2nd April 2051 19th April 2076 31st March 2002 28th March 2027 21st April 2052 11th April 2077 20th April 2003 16th April 2028 6th April 2053 3rd April 2078 11th April 2004 1st April 2029 29th March 2054 23rd April 2079 27th March 2005 21st April 2030 18th April 2055 7th April 2080 16th April 2006 13th April 2031 2nd April 2056 30th March 2081 8th April 2007 28th March 2032 22nd April 2057 19th April 2082 23rd March 2008 17th April 2033 14th April 2058 4th April 2083 12th April 2009 9th April 2034 30th March 2059 26th March 2084 4th April 2010 25th March 2035 18th April 2060 15th April 2085 24th April 2011 13th April 2036 10th April 2061 31st March 2086 8th April 2012 5th April 2037 26th March 2062 20th April 2087 31st March 2013 25th April 2038 15th April 2063 11th April 2088 20th April 2014 10th April 2039 6th April 2064 3rd April 2089 5th April 2015 1st April 2040 29th March 2065 16th April 2090 27th March 2016 21st April 2041 11th April 2066 8th April 2091 16th April 2017 6th April 2042 3rd April 2067 30th March 2092 1st April 2018 29th March 2043 22nd April 2068 12th April 2093 21st April 2019 17th April 2044 14th April 2069 4th April 2094 12th April 2020 9th April 2045 30th March 2070 24th April 2095 4th April 2021 25th March 2046 19th April 2071 15th April 2096 17th April 2022 14th April 2047 10th April 2072 31st March 2097 9th April 2023 5th April 2048 26th March 2073 20th April 2098 31st March 2024 18th April 2049 15th April 2074 12th April 2099

List of Easter Sunday Dates 2100-2199 |
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28th March 2100 22nd April 2125 12th April 2150 9th April 2175 17th April 2101 14th April 2126 4th April 2151 31st March 2176 9th April 2102 30th March 2127 23rd April 2152 20th April 2177 25th March 2103 18th April 2128 15th April 2153 5th April 2178 13th April 2104 10th April 2129 31st March 2154 28th March 2179 5th April 2105 26th March 2130 20th April 2155 16th April 2180 18th April 2106 15th April 2131 11th April 2156 1st April 2181 10th April 2107 6th April 2132 27th March 2157 21st April 2182 1st April 2108 19th April 2133 16th April 2158 13th April 2183 21st April 2109 11th April 2134 8th April 2159 28th March 2184 6th April 2110 3rd April 2135 23rd March 2160 17th April 2185 29th March 2111 22nd April 2136 12th April 2161 9th April 2186 17th April 2112 7th April 2137 4th April 2162 25th March 2187 2nd April 2113 30th March 2138 24th April 2163 13th April 2188 22nd April 2114 19th April 2139 8th April 2164 5th April 2189 14th April 2115 3rd April 2140 31st March 2165 25th April 2190 29th March 2116 26th March 2141 20th April 2166 10th April 2191 18th April 2117 15th April 2142 5th April 2167 1st April 2192 10th April 2118 31st March 2143 27th March 2168 21st April 2193 26th March 2119 19th April 2144 16th April 2169 6th April 2194 14th April 2120 11th April 2145 1st April 2170 29th March 2195 6th April 2121 3rd April 2146 21st April 2171 17th April 2196 29th March 2122 16th April 2147 12th April 2172 9th April 2197 11th April 2123 7th April 2148 4th April 2173 25th March 2198 2nd April 2124 30th March 2149 17th April 2174 14th April 2199

List of Easter Sunday Dates 2200-2299 |
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6th April 2200 27th March 2225 21st April 2250 18th April 2275 19th April 2201 16th April 2226 13th April 2251 2nd April 2276 11th April 2202 8th April 2227 28th March 2252 22nd April 2277 3rd April 2203 23rd March 2228 17th April 2253 14th April 2278 22nd April 2204 12th April 2229 9th April 2254 30th March 2279 7th April 2205 4th April 2230 25th March 2255 18th April 2280 30th March 2206 24th April 2231 13th April 2256 10th April 2281 19th April 2207 8th April 2232 5th April 2257 26th March 2282 3rd April 2208 31st March 2233 25th April 2258 15th April 2283 26th March 2209 20th April 2234 10th April 2259 6th April 2284 15th April 2210 5th April 2235 1st April 2260 22nd March 2285 31st March 2211 27th March 2236 21st April 2261 11th April 2286 19th April 2212 16th April 2237 6th April 2262 3rd April 2287 11th April 2213 1st April 2238 29th March 2263 22nd April 2288 27th March 2214 21st April 2239 17th April 2264 7th April 2289 16th April 2215 12th April 2240 2nd April 2265 30th March 2290 7th April 2216 4th April 2241 25th March 2266 19th April 2291 30th March 2217 17th April 2242 14th April 2267 10th April 2292 12th April 2218 9th April 2243 5th April 2268 26th March 2293 4th April 2219 31st March 2244 18th April 2269 15th April 2294 23rd April 2220 13th April 2245 10th April 2270 7th April 2295 15th April 2221 5th April 2246 2nd April 2271 19th April 2296 31st March 2222 28th March 2247 21st April 2272 11th April 2297 20th April 2223 16th April 2248 6th April 2273 3rd April 2298 11th April 2224 1st April 2249 29th March 2274 16th April 2299

How is Easter Sunday Date Determined? |
---|

### SUMMARY

Easter Sunday is the Sunday following the Paschal Full Moon (PFM) date for the year. (Paschal is pronounced "PAS-KUL", not "pas-chal"). See Christian Prayer Books for proof of this concise definition.

In June 325 A.D. astronomers approximated astronomical full moon dates for the Christian church, calling them Ecclesiastical Full Moon (EFM) dates. From 326 A.D. the PFM date has always been the EFM date after March 20 (which was the equinox date in 325 A.D.)

From 1583, each PFM date differs from an Astronomical Full Moon (AFM) date usually by no more than 1 date, and never by more than 3 dates. (Each AFM is a two-dates event due to world time zones. Each PFM is a one-date event world-wide).

### HISTORY

Easter Sunday is the date of the annual celebration of Christ's resurrection. The aim of the Easter Dating Method is to maintain, for each Easter Sunday, the same season of the year and the same relationship to the preceding astronomical full moon that occurred at the time of his resurrection in 30 A.D.

This was achieved in 1583 A.D. using skill and common-sense by Pope Gregory the 13th, and his astronomers and mathematicians, predominantly Lilius and Clavius, by introducing their new larger (revised) PFM Gregorian dates table. This replaced the (original) 326 A.D. "19 PFM dates" table in the Julian calendar.

Easter Sunday, from 326 A.D., is always one of the 35 dates March 22 to April 25.

From 31 A.D. to 325 A.D. Easter Day was celebrated either:

(a) on or just after the first day of the Jewish Passover (no matter on which day of the week that Easter Day occurred), or

(b) on a Sunday close to or on the first Passover Day.

Both of these methods existed continuously throughout this period.

From 326 A.D. to 1582 A.D. Easter Sunday date was based on the Julian calendar in use at that time. It became defined as the Sunday following the Paschal Full Moon date for the year, using a simple "19 PFM dates" table. Precise information on this subject can be found on pages 415 to 425 of the Explanatory Supplement to the 1961 Astronomical Ephemeris.

The Julian calendar was replaced by the Gregorian calendar in October 1582 to re-align March 20 (and therefore Easter) with the seasons by removing 10 dates October 5 to 14, 1582. This replacement did not occur until later in many countries e.g. in September 1752 in England. See GM Arts Easter Date Calculations for more information. ENGLISH Easter Sunday dates for 1583 to 1752 can be calculated using information near the end of this Easter Dating Method document.

The Gregorian calendar very closely maintains the alignment of seasons and calendar dates by having leap years in only 1 of every 4 century years, namely, those divisible exactly by 400. One additional February 29 date will need to be removed in about 4140 A.D., therefore Easter calculations will need to use the changed Days of Week of PFM dates when the exact year for this removal is decided.

From 326 A.D., the Easter Sunday Date for any given year is NOT determined by the March Equinox date for that year. March 20 (not March 21) is the most common Gregorian Equinox date from 1583 to 4099 A.D.

Historically, references to March 21 have caused mistakes in calculating Easter Sunday dates. March 20 has become the important date in recent Easter dating methods. Despite frequent references to March 21, this date has no special significance to any recent Easter dating methods.

The present method describing the Easter Dating Procedure can be found in Christian Prayer Books. This procedure has been dramatically simplified by Ronald W. Mallen, Adelaide, South Australia. See Finding Easter Sunday Dates with a Calculator for a clear and unique explanation of this procedure.

### ORTHODOX CHURCHES

Orthodox churches became fully autonomous in 1054 A.D., and celebrate their Easter always on the basis of the Julian calendar and the "19 PFM dates" table. The Julian calendar date Thursday October 4, 1582 was followed by the Gregorian calendar date Friday October 15, 1582. The 10 dates October 5 to 14 were removed.

Consequently, their Easter Sunday dates are identical up to 1582, then from 1583 onwards often differ from those of Western churches.

In some years the Orthodox Easter Sunday occurs on the same day as the Western Easter Sunday. For example, this occurred in 1990 because the Western Easter Sunday date of (Gregorian calendar) April 15, 1990 is the same as the Orthodox Easter Sunday date of (Julian calendar) April 2, 1990. In most years, Orthodox Easter follows Western Easter by one or more weeks.

To determine the Orthodox Easter Sunday date, it is first necessary to find the Julian Easter Sunday date, then to add the number of days which have been "skipped" in the Gregorian calendar. See Finding Orthodox Easter Sunday Dates with a Calculator for a simple explanation of this procedure.

Finding Easter Sunday Dates with a Calculator |
---|

This procedure is a dramatic and accurate simplification of the **official procedure** used to calculate Easter Sunday dates, as described in Christian Prayer Books. Paschal Full Moon dates are copied directly from these Books. It was produced in 1995 by Ronald W. Mallen, Adelaide, South Australia. It requires just one division on a calculator, and three simple additions.

This procedure appears more compactly in the 1988 Australian Almanac (titled "The Dating of Easter") held in the Canberra Library, Australia.

There are three steps to calculating the Easter Sunday date:

*Step 1)* Obtain the Paschal Full Moon (PFM) date from Table A

*Step 2)* Add the 3 numbers obtained from Tables B, C and D

*Step 3)* Find the Easter Sunday date from Table E

### STEP 1

Table A below shows PFM dates for years 326 to 2599 A.D. If you're looking further into the future, click here to see another Table A for years 2600 to 4099 A.D.

- Use a calculator to divide the year by 19
- Obtain the 3 digits
**after**the decimal point - Find the Paschal Full Moon (PFM) date in Table A below
- Then continue below with Step 2

Year 2285 example: 2285 **÷** 19 = 120**.**263157, so use the **.**263 part to find the PFM date in Table A. The result is March 21, 2285 A.D.

Fraction after dividing year by 19 |
326 - 1582 |
1583 - 1699 |
1700 - 1899 |
1900 - 2199 |
2200 - 2299 |
2300 - 2399 |
---|---|---|---|---|---|---|

2400 - 2499 |
2500 - 2599 |
|||||

.0 (none) |
A5 | A12 | A13 | A14 |
A15 | A16 |

.052 |
M25 | A1 | A2 | A3 |
A4 | A5 |

.105 |
A13 | M21 | M22 | M23 |
M24 | M25 |

.157 |
A2 | A9 | A10 | A11 |
A12 | A13 |

.210 |
M22 | M29 | M30 | M31 |
A1 | A2 |

.263 |
A10 | A17 | A18 | A18 |
M21 | M22 |

.315 |
M30 | A6 | A7 | A8 |
A9 | A10 |

.368 |
A18 | M26 | M27 | M28 |
M29 | M30 |

.421 |
A7 | A14 | A15 | A16 |
A17 | A18 |

.473 |
M27 | A3 | A4 | A5 |
A6 | A7 |

.526 |
A15 | M23 | M24 | M25 |
M26 | M27 |

.578 |
A4 | A11 | A12 | A13 |
A14 | A15 |

.631 |
M24 | M31 | A1 | A2 |
A3 | A4 |

.684 |
A12 | A18 | M21 | M22 |
M23 | M24 |

.736 |
A1 | A8 | A9 | A10 |
A11 | A12 |

.789 |
M21 | M28 | M29 | M30 |
M31 | A1 |

.842 |
A9 | A16 | A17 | A17 |
A18 | M21 |

.894 |
M29 | A5 | A6 | A7 |
A8 | A9 |

.947 |
A17 | M25 | M26 | M27 |
M28 | M29 |

### STEP 2

Add the 3 numbers you obtain from the "result" lines of Tables B, C and D below.

For example, the year 2285 gives us a PFM date of M21 in Table A (for years 326 to 2599 A.D.)

- M21 gives
**2**from Table B - the 22 in 2285 gives
**3**from Table C - the 85 in 2285 gives
**1**from Table D

The total of these results is: **2 + 3 + 1 = 6**

- | - | M21 | M22 | M23 | M24 | M25 | |

M26 | M27 | M28 | M29 | M30 | M31 | A1 | |

A2 | A3 | A4 | A5 | A6 | A7 | A8 | |

A9 | A10 | A11 | A12 | A13 | A14 | A15 | |

A16 | A17 | A18 | - | - | - | - | |

Result: | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
---|

- | - | - | - | 03 | 04 | 05 | |

06 | 07 | 08 | 09 | 10 | 11 | 12 | |

13 | 14 | 15* |
- | - | 15* |
16 | |

- | 17 | - | 18 | - | 19 | 20 | |

- | 21 | - | 22 | - | 23 | 24 | |

- | 25 | - | 26 | - | 27 | 28 | |

- | 29 | - | 30 | - | 31 | 32 | |

- | 33 | - | 34 | - | 35 | 36 | |

- | 37 | - | 38 | - | 39 | 40 | |

Result: | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
---|

***** for years 1500 to 1582, use the result of **4 *** for years 1583 to 1599, use the result of

**1**

00 | 01 | 02 | 03 | - | 04 | 05 | |

06 | 07 | - | 08 | 09 | 10 | 11 | |

- | 12 | 13 | 14 | 15 | - | 16 | |

17 | 18 | 19 | - | 20 | 21 | 22 | |

23 | - | 24 | 25 | 26 | 27 | - | |

28 | 29 | 30 | 31 | - | 32 | 33 | |

34 | 35 | - | 36 | 37 | 38 | 39 | |

- | 40 | 41 | 42 | 43 | - | 44 | |

45 | 46 | 47 | - | 48 | 49 | 50 | |

51 | - | 52 | 53 | 54 | 55 | - | |

56 | 57 | 58 | 59 | - | 60 | 61 | |

62 | 63 | - | 64 | 65 | 66 | 67 | |

- | 68 | 69 | 70 | 71 | - | 72 | |

73 | 74 | 75 | - | 76 | 77 | 78 | |

79 | - | 80 | 81 | 82 | 83 | - | |

84 | 85 | 86 | 87 | - | 88 | 89 | |

90 | 91 | - | 92 | 93 | 94 | 95 | |

- | 96 | 97 | 98 | 99 | - | - | |

Result: | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
---|

### STEP 3

Use the total result from step 2 to find the day of week of the PFM date in Table E, then add the number of days shown **to the PFM date** to find the Easter Sunday date.

For example, year 2285 gave us a PFM date of March 21, and step 2 gave us a total result of 6. Looking at Table E, this 6 shows that this PFM date occurs on a Saturday, so we need to add 1 day to find the next Sunday, which is March 22, the Easter Sunday date for the year 2285 A.D.

Step 2 result: |
0 | 1 | 2 | 3 | 4 | 5 | 6 |

7 | 8 | 9 | 10 | 11 | 12 | 13 | |

14 | 15 | 16 | 17 | 18 | - | - | |

Day of weekof PFM date: |
Sun | Mon | Tue | Wed | Thu | Fri | Sat |

Days to add fornext Sunday: |
7 | 6 | 5 | 4 | 3 | 2 | 1 |
---|

**Other examples:**

Julian calendar example:

Year 887: Step 1: PFM=A12, Step 2: 3+4+3 = 10, Step 3: A12+4 = April 16, 887

Gregorian calendar examples:

Year 1987: Step 1: PFM=A13, Step 2: 4+1+3 = 8, Step 3: A13+6 = April 19, 1987

Year 2987: Step 1: PFM=A4, Step 2: 2+5+3=10, Step 3: A4+4 = April 8, 2987

Year 3987: Step 1: PFM=M27, Step 2: 1+1+3=5, Step 3: M27+2 = March 29, 3987

**Table A - PFM Dates for Years 2600 - 4099**

- Use a calculator to divide the year by 19
- Obtain the 3 digits
**after**the decimal point - Find the Paschal Full Moon (PFM) date in Table A below
- Then click here to continue your calculation

Fraction after dividing year by 19 |
2600 - 2899 |
2900 - 3099 |
3100 - 3399 |
3400 - 3499 |
3500 - 3599 |
3800 - 4099 |
---|---|---|---|---|---|---|

3600 - 3699 |
3700 - 3799 |
|||||

.0 (none) |
A17 | A18 | A18 | M21 | M22 | M23 |

.052 |
A6 | A7 | A8 | A9 | A10 | A11 |

.105 |
M26 | M27 | M28 | M29 | M30 | M31 |

.157 |
A14 | A15 | A16 | A17 | A18 | A18 |

.210 |
A3 | A4 | A5 | A6 | A7 | A8 |

.263 |
M23 | M24 | M25 | M26 | M27 | M28 |

.315 |
A11 | A12 | A13 | A14 | A15 | A16 |

.368 |
M31 | A1 | A2 | A3 | A4 | A5 |

.421 |
A18 | M21 | M22 | M23 | M24 | M25 |

.473 |
A8 | A9 | A10 | A11 | A12 | A13 |

.526 |
M28 | M29 | M30 | M31 | A1 | A2 |

.578 |
A16 | A17 | A17 | A18 | M21 | M22 |

.631 |
A5 | A6 | A7 | A8 | A9 | A10 |

.684 |
M25 | M26 | M27 | M28 | M29 | M30 |

.736 |
A13 | A14 | A15 | A16 | A17 | A17 |

.789 |
A2 | A3 | A4 | A5 | A6 | A7 |

.842 |
M22 | M23 | M24 | M25 | M26 | M27 |

.894 |
A10 | A11 | A12 | A13 | A14 | A15 |

.947 |
M30 | M31 | A1 | A2 | A3 | A4 |

Finding Orthodox Easter Sunday Dates with a Calculator |
---|

This accurate procedure applies to Orthodox churches, which always base their calculations on the Julian calendar and the "19 PFM dates" table. It applies from the year 1054 A.D., and takes no account whatsoever of the changes resulting from the introduction of the Gregorian calendar in 1582. This is the current situation in 2002.

These instructions show the procedure for years 1054 to 3399 A.D. However, this simple method continues indefinitely, because the Julian calendar always has a February 29 date in **every** fourth year.

There are four steps to calculating the Orthodox Easter Sunday date:

*Step 1)* Obtain the Paschal Full Moon (PFM) date from Table A

*Step 2)* Add the 3 numbers obtained from Tables B, C and D

*Step 3)* Find the Julian Orthodox Easter Sunday date from Table E

*Step 4)* Convert this Julian date to the Gregorian calendar date from Table F

### STEP 1

Table A below shows PFM dates from 1054 AD.

- Use a calculator to divide the year by 19
- Obtain the 3 digits
**after**the decimal point - Find the Paschal Full Moon (PFM) date in Table A below
- Then continue below with Step 2

Year 1995 example: 1995 **÷** 19 = 105 exactly, so use the digits after the decimal point (none in this case) to find the PFM date in Table A. The result is April 5, 1995.

Fraction after dividing year by 19 |
PFM Date |
---|---|

.0 (none) |
A5 |

.052 |
M25 |

.105 |
A13 |

.157 |
A2 |

.210 |
M22 |

.263 |
A10 |

.315 |
M30 |

.368 |
A18 |

.421 |
A7 |

.473 |
M27 |

.526 |
A15 |

.578 |
A4 |

.631 |
M24 |

.684 |
A12 |

.736 |
A1 |

.789 |
M21 |

.842 |
A9 |

.894 |
M29 |

.947 |
A17 |

### STEP 2

Add the 3 numbers you obtain from the "result" lines of Tables B, C and D below.

For example, the year 1995 gave us a PFM date of A5 in Table A

- A5 gives
**3**from Table B - the 19 in 1995 gives
**0**from Table C - the 95 in 1995 gives
**6**from Table D

The total of these results is: **3 + 0 + 6 = 9**

- | - | M21 | M22 | M23 | M24 | M25 | |

M26 | M27 | M28 | M29 | M30 | M31 | A1 | |

A2 | A3 | A4 | A5 | A6 | A7 | A8 | |

A9 | A10 | A11 | A12 | A13 | A14 | A15 | |

A16 | A17 | A18 | - | - | - | - | |

Result: | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
---|

- | - | - | - | 10 | 11 | 12 | |

13 | 14 | 15 | 16 | 17 | 18 | 19 | |

20 | 21 | 22 | 23 | 24 | 25 | 26 | |

27 | 28 | 29 | 30 | 31 | 32 | 33 | |

Result: | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
---|

00 | 01 | 02 | 03 | - | 04 | 05 | |

06 | 07 | - | 08 | 09 | 10 | 11 | |

- | 12 | 13 | 14 | 15 | - | 16 | |

17 | 18 | 19 | - | 20 | 21 | 22 | |

23 | - | 24 | 25 | 26 | 27 | - | |

28 | 29 | 30 | 31 | - | 32 | 33 | |

34 | 35 | - | 36 | 37 | 38 | 39 | |

- | 40 | 41 | 42 | 43 | - | 44 | |

45 | 46 | 47 | - | 48 | 49 | 50 | |

51 | - | 52 | 53 | 54 | 55 | - | |

56 | 57 | 58 | 59 | - | 60 | 61 | |

62 | 63 | - | 64 | 65 | 66 | 67 | |

- | 68 | 69 | 70 | 71 | - | 72 | |

73 | 74 | 75 | - | 76 | 77 | 78 | |

79 | - | 80 | 81 | 82 | 83 | - | |

84 | 85 | 86 | 87 | - | 88 | 89 | |

90 | 91 | - | 92 | 93 | 94 | 95 | |

- | 96 | 97 | 98 | 99 | - | - | |

Result: | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
---|

### STEP 3

Use the total result from step 2 to find the day of week of the PFM date in Table E, then add the number of days shown **to the PFM date** to find the Julian calendar Easter Sunday date.

For example, year 1995 gave us a PFM date of April 5, and step 2 gave us a total result of 9. Looking at Table E, this 9 shows that this PFM date occurs on a Tuesday, so we need to add 5 days to find the next Sunday, which is April 10. This date is the Julian calendar Orthodox Easter Sunday date for year 1995.

If the year itself is also Julian (e.g. for Greece in years 1054 to 1922) then this Julian date (e.g. April 3 in 1922) is their Orthodox Easter Sunday date for that year.

ENGLAND used the Julian calendar until 1752, so its Easter Sunday dates are obtained by using steps 1, 2 and 3 (but not 4) of the Orthodox Method stated here. For example, **English** Easter Sunday date for 1750 A.D. = A13 + 2 = April 15 in the Julian calendar. From 1753 England adopted the (revised) PFM Gregorian dates Table A and subsequent tables used in the calculations above.

Step 2 result: |
0 | 1 | 2 | 3 | 4 | 5 | 6 |

7 | 8 | 9 | 10 | 11 | 12 | 13 | |

14 | 15 | 16 | 17 | 18 | - | - | |

Day of weekof PFM date: |
Sun | Mon | Tue | Wed | Thu | Fri | Sat |

Days to add fornext Sunday: |
7 | 6 | 5 | 4 | 3 | 2 | 1 |
---|

### STEP 4

The Gregorian calendar omits certain February 29 dates to keep its dates aligned with the seasons and position of Earth in relation to the Sun. To convert the Julian date to the Gregorian date, it is necessary to add the number of days shown in Table F.

**Step 4 must be ignored if the Easter Sunday date calculated after step 3 occurred when the Julian calendar was still in use.**

The example for year 1995 gives the Julian Easter Sunday date of April 10, and Table F shows that we need to add 13 days to convert it to the Gregorian calendar date of April 23. This date is the Gregorian calendar Orthodox Easter Sunday date for year 1995 A.D.

Year | Days to Add |
---|---|

1583 to 1699 | 10 |

1700 to 1799 | 11 |

1800 to 1899 | 12 |

1900 to 2099 | 13 |

2100 to 2199 | 14 |

2200 to 2299 | 15 |

2300 to 2499 | 16 |

2500 to 2599 | 17 |

2600 to 2699 | 18 |

2700 to 2899 | 19 |

2900 to 2999 | 20 |

3000 to 3099 | 21 |

3100 to 3299 | 22 |

3300 to 3399 | 23 |

**Other examples:**

Year 1994: Step 1: PFM=A17, Step 2: 1+0+5 = 6, Step 3: A17+1=Julian April 18, 1994, Step 4: Julian A18 + 13 = Gregorian May 1, 1994

Year 2870: Step 1: PFM=M25, Step 2: 6+5+3 = 14, Step 3: M25+7=Julian April 1, 2870, Step 4: Julian A1 + 19 = Gregorian April 20, 2870

Easter Algorithm for a Computer Program |
---|

Here is an algorithm written in BASIC to calculate the Gregorian Easter Sunday date for years 1583 to 4099 (Western churches only). BASIC code is fairly straightforward, and can easily be converted to other programming languages.

**Some typical questions about Easter are:**

Q1) "When was Easter Sunday last on April 10?"

Q2) "When does Good Friday next occur on March 30?"

Q3) "How many times has Easter Sunday occurred on April 25 since 1583?"

Answers to these questions can be determined by placing this code within DO...WHILE or FOR...NEXT loops to search or count.

Sub EasterDate (d, m, y)' EASTER DATE CALCULATION FOR YEARS 1583 TO 4099 ' y is a 4 digit year 1583 to 4099 ' d returns the day of the month of Easter ' m returns the month of Easter ' Easter Sunday is the Sunday following the Paschal Full Moon ' (PFM) date for the year ' This algorithm is an arithmetic interpretation of the 3 step ' Easter Dating Method developed by Ron Mallen 1985, as a vast ' improvement on the method described in the Common Prayer Book ' Because this algorithm is a direct translation of the ' official tables, it can be easily proved to be 100% correct ' This algorithm derives values by sequential inter-dependent ' calculations, so ... DO NOT MODIFY THE ORDER OF CALCULATIONS! ' The\operator may be unfamiliar - it means integer division ' for example, 30 \ 7 = 4 (the remainder is ignored) ' All variables are integer data types ' It's free! Please do not modify code or comments! ' ========================================================== Dim FirstDig, Remain19, temp 'intermediate results Dim tA, tB, tC, tD, tE 'table A to E results FirstDig = y \ 100 'first 2 digits of year Remain19 = y Mod 19 'remainder of year / 19 ' calculate PFM date temp = (FirstDig - 15) \ 2 + 202 - 11 * Remain19 Select Case FirstDig Case 21, 24, 25, 27 To 32, 34, 35, 38 temp = temp - 1 Case 33, 36, 37, 39, 40 temp = temp - 2 End Select temp = temp Mod 30 tA = temp + 21 If temp = 29 Then tA = tA - 1 If (temp = 28 And Remain19 > 10) Then tA = tA - 1 'find the next Sunday tB = (tA - 19) Mod 7 tC = (40 - FirstDig) Mod 4 If tC = 3 Then tC = tC + 1 If tC > 1 Then tC = tC + 1 temp = y Mod 100 tD = (temp + temp \ 4) Mod 7 tE = ((20 - tB - tC - tD) Mod 7) + 1 d = tA + tE 'return the date If d > 31 Then d = d - 31 m = 4 Else m = 3 End If End Sub

**If you have any questions regarding the information presented here, please e-mail Ron Mallen at rwmallen@chariot.net.au**

This **disclaimer** applies to this document:

If you are using these dates to plan travel, meetings, or for any use requiring the expenditure of money, time, or other resources, please consult other sources to verify the dates of Easter holidays. Neither R. W. Mallen or anyone who owns the hardware or manages the host machines of this home page, or the Astronomical Society of South Australia, nor anyone who has contributed any information that has been used in this document, may be held financially responsible, or responsible in any way, if these dates are incorrectly calculated or applied. The user assumes full responsibility for the consequences of using this information.