I |
Add one to the year you are given. |
2011 + 1 |
= 2012 |
II |
Divide the year by four, rounded down. |
2011 / 4 |
= 502 |
III |
From the centuries, take sixteen (if you can) |
20 – 16 |
= 4 |
IV |
And divide that by four, rounded down. |
4 / 4 |
= 1 |
V |
Add I, II and IV, then take away III, |
2011 + 502 + 1 – 4 |
= 2511 |
VI |
Then take that value modulo seven |
2551 mod 7 |
= 5 |
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(Divide by seven and keep the remainder) |
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Subtracting from seven again: |
7 – 5 |
= 2 |
VII |
The year’s dominical letter. |
2 |
= B |
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(We’ll use it as if it’s a number.) |
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VIII |
Take I mod nineteen (if it’s zero, nineteen) |
2012 mod 19 |
= 17 |
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This is the year’s golden number. |
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Now take seventeen from the centuries, |
20 – 17 |
= 3 |
IX |
Over twenty-five (chuck the remainder) |
3 / 5 |
= 0 |
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Take IX and 15 from the centuries |
20 – 0 – 15 |
= 5 |
X |
Over three (and chuck the remainder) |
5 / 3 |
= 1 |
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To VIII, add ten times (VIII minus one) |
17 + 10 * 16 |
= 177 |
XI |
Take that sum modulo thirty |
177 mod 30 |
= 27 |
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Add XI, X and IV and then take away III, |
(27 + 1 + 1 – 4) |
= 25 |
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(If it’s large enough, modulo thirty) |
25 mod 30 |
= 25 |
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If it be twenty-four, make it twenty-five; |
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If twenty-five, and if VIII is more than eleven |
(17 > 11) |
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Make it twenty-six instead; |
25 |
= 26 |
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If it’s zero, set it to thirty. |
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XII |
The result is the epact; a good Scrabble word, |
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26 |
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The age of the moon on New Years’ Day. |
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If the epact is less than twenty-four, |
(no) |
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XIII(b) |
Subtract it from forty-five (write that down) |
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Then subtract the epact from twenty-seven |
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Divide that by seven and keep the remainder: |
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XIV(b) |
If it’s zero, change it to seven. |
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If the epact is higher than twenty-three, |
(26 > 23) |
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XIII(b) |
Subtract it from seventy-five instead |
75 – 26 |
= 49 |
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Then subtract the epact from fifty-seven, |
57 – 26 |
= 31 |
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Divide that by seven and keep the remainder: |
31 mod 7 |
= 3 |
XIV(b) |
If it’s zero, change it to seven. |
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= 3 |
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Then add XIII to VII (the dominical number). |
49 + 2 |
= 51 |
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If XIV’s more than VII, add seven more. |
(3 > 2) 51 + 7 |
= 58 |
XV |
And then take away what you got for XIV. |
58 – 3 |
= 55 |
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If the result is below thirty-two, |
(no) |
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Easter Sunday’s in March, and that’s the date, |
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Otherwise, it’s in April – subtract thirty-one. |
55 – 31 |
= 24 April |