Littell's Living Age/Volume 129/Issue 1660/Miscellany

The Date of Easter. — We revert to this subject with the view to reproduce the arithmetical rule to find Easter Sunday in the Gregorian calendar, which was first given by the eminent German mathematician and astronomer Gauss, in Zach's Monatliche Correspondenz, 1800.

1.	From 1800 to 1899 put m = 23, n = 4.    "    1900 to 2099  "   m = 24, n = 5.
2.	Divide the given year by 19, and call the remainder	a.
3.	Divide the given year by 4, and call the remainder	b.
4.	Divide the given year by 7, and call the remainder	c.
5.	Add m to 19 times a, divide the sum by 30, and call the remainder	d.
6.	Add together n, twice b, four times c, and six times d, divide the sum by 7, and call the remainder	e.

Then Easter Sunday is March 22 + d + e, or d + e - 9 of April.

To apply this rule to the present year, we have —

1.	m = 23; n = 4.
2.	For ${\tfrac {1876}{19}}\,$ remainder is 14	a.
3.	For ${\tfrac {1876}{4}}\,$ remainder is 0	b.
4.	For ${\tfrac {1876}{7}}\,$ remainder is 0	c.
5.	For ${\tfrac {23+19\times 14}{30}}\,$ remainder is 19	d.
6.	For ${\tfrac {4+0+0+6\times 19}{7}}\,$ remainder is 6	e.

And Easter Sunday is March 22 + 19 + 6 = March 47 or April 16; or 19 + 6 - 9 of April = April 16.

Note. — The following are the two exceptions to the above rule: —

1. If Easter Sunday is brought out April 26, we must take April 19.
2. If Easter Sunday results on April 25 by the rule, the 18th must be substituted when the given year, increased by one, and then divided by 19, leaves a remainder greater than 11.

Nature.