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:

ydayMaxEarth: If it is an Earth leap year, 366; else, 365.
ydayMax: Start with 389.; If it is an Earth leap year, add one.; 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: $\text{ydayPre} \pmod{\text{ydayMaxEarth}}$; If yday is between zero (inclusive) and one (exclusive), then yday is ydayMax.
lythryd: $\lceil \frac{\text{yday}}{32} \rceil$
day: $\lfloor \text{yday} - \text{lythryd} * 32 \pmod{32} \rfloor$

@@ Line 23: / Line 23: @@
 To calculate the result:
 ;<code>year</code>
+:<math mode="display">\text{year} - 892</math>
-:Start with the current year minus 892.
 :If <code>ydayPre</code> is less than zero, subtract one.
 ;<code>ydayPre</code>