Module:Keppel date/doc: Difference between revisions

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Converts the current (or provided) date to a Keppel date. Used by Template:Keppel date.

Begin with the following inputs:

First, we define the following:

Earth leap year: $\text{year} \bmod{400}$; $\text{year} \bmod{4}\text{ and not }\text{year} \bmod{100}$
ydayMaxEarth: If it is an Earth leap year, 366; else, 365.
ydayMax: Start with 389.; If it is a Keppel leap year (schedule 1), add one.; If it is a Keppel leap year (schedule 2), add one.
rolloverOffset: If it is an Earth leap year, 79; else, 78.

To calculate the result:

year: $\text{year} - 892$; If ydayPre is less than zero, subtract one.
ydayPre: $\frac{\text{ydayMax} * (\text{yday} - \text{rolloverOffset})}{\text{ydayMaxEarth}}$
yday: $\text{ydayPre} \bmod{\text{ydayMaxEarth}}$; If yday is between zero (inclusive) and one (exclusive), then yday is ydayMax.
lythryd: $\lceil \frac{\text{yday}}{32} \rceil$
day: $\lfloor \text{yday} - \text{lythryd} * 32 \bmod{32} \rfloor$

@@ Line 11: / Line 11: @@
 First, we define the following:
+;Earth leap year
+:<math mode="display">\text{year} \bmod{400}</math>
+:<math mode="display">\text{year} \bmod{4}\text{ and not }\text{year} \bmod{100}</math>
 ;<code>ydayMaxEarth</code>
 :If it is an Earth leap year, 366; else, 365.
@@ Line 27: / Line 30: @@
 :<math mode="display">\frac{\text{ydayMax} * (\text{yday} - \text{rolloverOffset})}{\text{ydayMaxEarth}}</math>
 ;<code>yday</code>
-:<math mode="display">\text{ydayPre} \pmod{\text{ydayMaxEarth}}</math>
+:<math mode="display">\text{ydayPre} \bmod{\text{ydayMaxEarth}}</math>
 :If <code>yday</code> is between zero (inclusive) and one (exclusive), then <code>yday</code> is <code>ydayMax</code>.
 ;<code>lythryd</code>
 :<math mode="display">\lceil \frac{\text{yday}}{32} \rceil</math>
 ;<code>day</code>
-:<math mode="display">\lfloor \text{yday} - \text{lythryd} * 32 \pmod{32} \rfloor</math>
+:<math mode="display">\lfloor \text{yday} - \text{lythryd} * 32 \bmod{32} \rfloor</math>
 <includeonly>[[Category:Modules: tesinormed]]</includeonly>