XII. To XI. add X. and IV., and take away III., throwing out thirties, if any. If this give 24, change it into 25. If 25, change it into 26, whenever the golden number is greater than 11. If 0, change it into 30. Thus we have the epact, or age of the _Calendar_ moon at the beginning of the year. (6). _When the Epact is 23, or less._ XIII. Subtract XII., the epact, from 45. (39). XIV. Subtract the epact from 27, divide by 7, and keep the remainder, or 7, if there be no remainder. (7) _When the Epact is greater than 23._ XIII. Subtract XII., the epact, from 75. XIV. Subtract the epact from 57, divide by 7, and keep the remainder, or 7, if there be no remainder. XV. To XIII. add VII., the dominical number, (and 7 besides, if XIV. be greater than VII.,) and subtract XIV., the result is the day of March, or if more than 31, subtract 31, and {367} the result is the day of April, on which Easter Sunday falls. (39; Easter Day is April 8). In the following examples, the several results leading to the final conclusion are tabulated. ======================================================== GIVEN YEAR | 1592 | 1637 | 1723 | 1853 | 2018 | 4686 -------------------------------------------------------- I. | 1593 | 1638 | 1724 | 1854 | 2019 | 4687 II. | 398 | 409 | 430 | 463 | 504 | 1171 III. | --- | 0 | 1 | 2 | 4 | 30 IV. | --- | 0 | 0 | 0 | 1 | 7 V. | 1991 | 2047 | 2153 | 2315 | 2520 | 5835 VI. | 3 | 3 | 4 | 5 | 0 | 4 VII. | 4 | 4 | 3 | 2 | 7 | 3 VIII. | 16 | 4 | 14 | 11 | 5 | 13 IX. | --- | --- | 0 | 0 | 0 | 1 X. | 0 | 0 | 0 | 1 | 1 | 10 XI. | 16 | 4 | 24 | 21 | 15 | 13 XII. | 16 | 4 | 23 | 20 | 13 |0 say 30 XIII. | 29 | 41 | 22 | 25 | 32 | 45 XIV. | 4 | 2 | 4 | 7 | 7 | 6 XV. | 29 | 43 | 28 | 27 | 32 | 49 Easter Day |Mar.29|Apr.12|Mar.28|Mar.27|Apr.1 | Apr.18 -------------------------------------------------------- 13. _Rule for determining Easter Day of the Antegregorian Calendar in any year of the old style._ To the several parts of the rule are annexed, by way of example, the results for the year 1287. The steps are numbered to correspond with the steps of the Gregorian rule, so that it can be seen what augmentations the latter requires. I. Set down the given year. (1287). II. Take the quotient of the given year divided by 4, neglecting the remainder (321). V. Take 4 more than the sum of I. and II. (1612). VI. Find the remainder of V. divided by 7. (2). VII. Subtract VI. from 7; this is the number of the dominical letter 1 2 3 4 5 6 7 (5; dominical letter E). A B C D E F G