What are these numbers used for chinese lunar calendar conversions? - calendar

Question

I'm developing an application about bank holidays in many countries.
To find bank holidays dates in China I need to convert dates to Chinese system.
I have found many libraries in different languages, like :
this one : https://github.com/v5developer/maven-framework-project/blob/master/aimeizi-tutorials/src/main/java/net/aimeizi/tutorials/LunarCalendar.java that I transposed to Apex language
this one https://www.javascriptbank.com/javascript/time/Lunar_Calendar_script/amlich-hnd.js in js (it's for Vietnam but seems to work about the same)
or this one https://github.com/magiclen/JavaChineseCalendar/blob/master/src/main/java/org/magiclen/%E8%BE%B2%E6%9B%86/%E8%BE%B2%E6%9B%86.java
and more.
All of them use an array of numbers, with one number per year, like this one :
final static long[] lunarInfo = new long[] { 0x04bd8, 0x04ae0, 0x0a570,
0x054d5, 0x0d260, 0x0d950, 0x16554, 0x056a0, 0x09ad0, 0x055d2,
0x04ae0, 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540, 0x0d6a0,
0x0ada2, 0x095b0, 0x14977, 0x04970, 0x0a4b0, 0x0b4b5, 0x06a50,
0x06d40, 0x1ab54, 0x02b60, 0x09570, 0x052f2, 0x04970, 0x06566,
0x0d4a0, 0x0ea50, 0x06e95, 0x05ad0, 0x02b60, 0x186e3, 0x092e0,
0x1c8d7, 0x0c950, 0x0d4a0, 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4,
0x025d0, 0x092d0, 0x0d2b2, 0x0a950, 0x0b557, 0x06ca0, 0x0b550,
0x15355, 0x04da0, 0x0a5d0, 0x14573, 0x052d0, 0x0a9a8, 0x0e950,
0x06aa0, 0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260,
0x0f263, 0x0d950, 0x05b57, 0x056a0, 0x096d0, 0x04dd5, 0x04ad0,
0x0a4d0, 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b5a0, 0x195a6,
0x095b0, 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40,
0x0af46, 0x0ab60, 0x09570, 0x04af5, 0x04970, 0x064b0, 0x074a3,
0x0ea50, 0x06b58, 0x055c0, 0x0ab60, 0x096d5, 0x092e0, 0x0c960,
0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0,
0x092d0, 0x0cab5, 0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9,
0x04ba0, 0x0a5b0, 0x15176, 0x052b0, 0x0a930, 0x07954, 0x06aa0,
0x0ad50, 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65,
0x0d530, 0x05aa0, 0x076a3, 0x096d0, 0x04bd7, 0x04ad0, 0x0a4d0,
0x1d0b6, 0x0d250, 0x0d520, 0x0dd45, 0x0b5a0, 0x056d0, 0x055b2,
0x049b0, 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0 };
used to calculate various numbers, like in
final private static int yearDays(int y) {
int i, sum = 348;
for (i = 0x8000; i > 0x8; i >>= 1) {
if ((lunarInfo[y - 1900] & i) != 0)
sum += 1;
}
return (sum + leapDays(y));
}
final private static int leapDays(int y) {
if (leapMonth(y) != 0) {
if ((lunarInfo[y - 1900] & 0x10000) != 0)
return 30;
else
return 29;
} else
return 0;
}
I've been searching in libraries comments, documentations, gerneral info about China, and I learnt a lot about the chinese calendar but couldn't find what these numbers are.... and where they come from.
It doesn't prevent me from using it but I like to understand what I code... Any explanations ?
Thanks

Answer 1

I finally came to understand that, at least for this code https://github.com/v5developer/maven-framework-project/blob/master/aimeizi-tutorials/src/main/java/net/aimeizi/tutorials/LunarCalendar.java, it's just a way to store data :
The data is encoded on 17 bits with :
bit 17 : number of days in leap month , 1=>30, 0=>29
bits 16 to 5 : number of days in each month, 0=>29, 1=>30
bits 4 to 1 : number of the leap month in the year in binary.
So 0x16554 (7th in the list, so year 1906) is 10110010101010100 in binary with a 17 bits length, which means :
10110010101010100 : There is a leap month, it's month 4
10110010101010100 : The leap month has 30 days
10110010101010100 : The 1st month has 29 days
10110010101010100 : The 2nd month has 30 days
...
10110010101010100 : The 12th month has 30 days
which can be checked here : https://www.asia-home.com//china/calendrier-chinois/year/1906.php
In other codes the meaning can vary but the idea is the same.