public static int getNewMoonDay(int k, double timeZone)
{
double jd = VietCalendar.NewMoon(k);
return(VietCalendar.INT((jd + (0.5
+ (timeZone / 24)))));
}
public static double SunLongitudeAA98(double jdn)
{
double T = ((jdn - 2451545)
/ 36525);
// Time in Julian centuries from 2000-01-01 12:00:00 GMT
double T2 = (T * T);
double dr = (PI / 180);
// degree to radian
double M = (357.5291
+ ((35999.0503 * T)
- ((0.0001559 * T2) - (4.8E-07
* (T * T2)))));
// mean anomaly, degree
double L0 = (280.46645
+ ((36000.76983 * T) + (0.0003032 * T2)));
// mean longitude, degree
double DL = ((1.9146
- ((0.004817 * T) - (1.4E-05 * T2)))
* Math.Sin((dr * M)));
DL = (DL
+ (((0.019993 - (0.000101 * T))
* Math.Sin((dr * (2 * M)))) + (0.00029 * Math.Sin((dr * (3 * M))))));
double L = (L0 + DL);
// true longitude, degree
L = (L - (360 * VietCalendar.INT((L / 360))));
// Normalize to (0, 360)
return(L);
}
// Am lich sang Duong lich
public static int[] convertLunar2Solar(int lunarDay, int lunarMonth, int lunarYear, int lunarLeap, double timeZone)
{
int b11;
int a11;
if ((lunarMonth < 11))
{
a11 = VietCalendar.getLunarMonth11((lunarYear - 1), timeZone);
b11 = VietCalendar.getLunarMonth11(lunarYear, timeZone);
}
else
{
a11 = VietCalendar.getLunarMonth11(lunarYear, timeZone);
b11 = VietCalendar.getLunarMonth11((lunarYear + 1), timeZone);
}
int k = VietCalendar.INT((0.5
+ ((a11 - 2415021.0769986948)
/ 29.530588853)));
int off = (lunarMonth - 11);
if ((off < 0))
{
off += 12;
}
if (((b11 - a11)
> 365))
{
int leapOff = VietCalendar.getLeapMonthOffset(a11, timeZone);
int leapMonth = (leapOff - 2);
if ((leapMonth < 0))
{
leapMonth += 12;
}
if (((lunarLeap != 0) &&
(lunarMonth != leapMonth)))
{
// System.out.println("Invalid input!");
return(new int[] {
0,
0,
0
});
}
else if (((lunarLeap != 0) ||
(off >= leapOff)))
{
off++;
}
}
int monthStart = VietCalendar.getNewMoonDay((k + off), timeZone);
return(VietCalendar.jdToDate((monthStart
+ (lunarDay - 1))));
}
public static int getLunarMonth11(int yy, double timeZone)
{
double off = (VietCalendar.jdFromDate(31, 12, yy) - 2415021.0769986948);
int k = VietCalendar.INT((off / 29.530588853));
int nm = VietCalendar.getNewMoonDay(k, timeZone);
int sunLong = VietCalendar.INT((VietCalendar.getSunLongitude(nm, timeZone) / 30));
if ((sunLong >= 9))
{
nm = VietCalendar.getNewMoonDay((k - 1), timeZone);
}
return(nm);
}
public static int getLeapMonthOffset(int a11, double timeZone)
{
int k = VietCalendar.INT((0.5
+ ((a11 - 2415021.0769986948)
/ 29.530588853)));
int last;
// Month 11 contains point of sun longutide 3*PI/2 (December solstice)
int i = 1;
// We start with the month following lunar month 11
int arc = VietCalendar.INT((VietCalendar.getSunLongitude(VietCalendar.getNewMoonDay((k + i), timeZone), timeZone) / 30));
do
{
last = arc;
i++;
arc = VietCalendar.INT((VietCalendar.getSunLongitude(VietCalendar.getNewMoonDay((k + i), timeZone), timeZone) / 30));
} while (((arc != last) &&
(i < 14)));
return(i - 1);
}
// Duong lich sang Am lich
public static int[] convertSolar2Lunar(int dd, int mm, int yy, double timeZone)
{
int lunarLeap;
int lunarDay;
int lunarMonth;
int lunarYear;
int dayNumber = VietCalendar.jdFromDate(dd, mm, yy);
int k = VietCalendar.INT(((dayNumber - 2415021.0769986948)
/ 29.530588853));
int monthStart = VietCalendar.getNewMoonDay((k + 1), timeZone);
if ((monthStart > dayNumber))
{
monthStart = VietCalendar.getNewMoonDay(k, timeZone);
}
int a11 = VietCalendar.getLunarMonth11(yy, timeZone);
int b11 = a11;
if ((a11 >= monthStart))
{
lunarYear = yy;
a11 = VietCalendar.getLunarMonth11((yy - 1), timeZone);
}
else
{
lunarYear = (yy + 1);
b11 = VietCalendar.getLunarMonth11((yy + 1), timeZone);
}
lunarDay = ((dayNumber - monthStart)
+ 1);
int diff = VietCalendar.INT(((monthStart - a11)
/ 29));
lunarLeap = 0;
lunarMonth = (diff + 11);
if (((b11 - a11)
> 365))
{
int leapMonthDiff = VietCalendar.getLeapMonthOffset(a11, timeZone);
if ((diff >= leapMonthDiff))
{
lunarMonth = (diff + 10);
if ((diff == leapMonthDiff))
{
lunarLeap = 1;
}
}
}
if ((lunarMonth > 12))
{
lunarMonth = (lunarMonth - 12);
}
if (((lunarMonth >= 11) &&
(diff < 4)))
{
lunarYear--;
}
return(new int[] {
lunarDay,
lunarMonth,
lunarYear,
lunarLeap
});
}