public JulianDay ToJulianDay()
{
int N = this.Day + AstroMath.Int(29.5001 * (this.Month - 1) + 0.99);
int Q = AstroMath.Int(this.Year / 30);
int R = this.Year % 30;
int A = AstroMath.Int(((11 * R) + 3) / 30);
int W = (404 * Q) + (354 * R) + 208 + A;
int Q1 = AstroMath.Int(W / 1461);
int Q2 = W % 1461;
int G = 621 + 4 * (AstroMath.Int((7 * Q) + Q1));
int K = AstroMath.Int(Q2 / 365.2422);
int E = AstroMath.Int(365.2422 * K);
int J = Q2 - E + N - 1;
int X = G + K;
if ((J > 366) && (X % 4 == 0))
{
J = J - 366;
X = X + 1;
}
if ((J > 354) && (X % 4 > 0))
{
J = J - 365;
X = X + 1;
}
double JD = AstroMath.Int(365.25 * (X - 1)) + 1721423 + J;
return(new JulianDay(JD));
}
public static JulianDay Pesach(int Year)
{
if (Year < -3761)
{
throw new ArgumentOutOfRangeException("Year", "The Hebrew Calendar is not valid prior to 3761 BCE");
}
int X = Year;
int month = 3;
int C = AstroMath.Int(X / 100);
int S = AstroMath.Int((C * 3 - 5) / 4);
int A = X + 3760;
int a = AstroMath.Mod(X * 12 + 12, 19);
int b = AstroMath.Mod(X, 4);
if (X < 1583)
{
S = 0;
}
double Q = -1.904412361576 + 1.554241796621 * a + 0.25 * b - 0.003177784022 * X + S;
int j = AstroMath.Mod(AstroMath.Int(Q) + 3 * X + 5 * b + 2 - S, 7);
double r = Q - AstroMath.Int(Q);
int D;
if (j == 2 || j == 4 || j == 6)
{
D = AstroMath.Int(Q) + 23;
}
else if (j == 1 && a > 6 && r >= 0.632870370)
{
D = AstroMath.Int(Q) + 24;
}
else if (j == 0 && a > 11 && r >= 0.897723765)
{
D = AstroMath.Int(Q) + 23;
}
else
{
D = AstroMath.Int(Q) + 22;
}
if (D > 31)
{
month = month + 1;
D = D - 31;
}
/* Debug information */
Debug.WriteLine("X\t= " + X);
Debug.WriteLine("C\t= " + C);
Debug.WriteLine("S\t= " + S);
Debug.WriteLine("A\t= " + A);
Debug.WriteLine("a\t= " + a);
Debug.WriteLine("b\t= " + b);
Debug.WriteLine("Q\t= " + Q);
Debug.WriteLine("j\t= " + j);
Debug.WriteLine("r\t= " + r);
Debug.WriteLine("D\t= " + D);
return(new JulianDay(Year, month, D));
}
public override int GetHashCode()
{
return(AstroMath.Int(this.JulianDayNumber));
}
public static IslamicCalendar FromJulianDay(JulianDay JD)
{
int X = JD.Year;
int M = JD.Month;
int D = JD.Day;
if (M < 3)
{
X = X - 1;
M = M + 12;
}
int α = AstroMath.Int(X / 100);
int β = 2 - α + AstroMath.Int(α / 4);
int b = AstroMath.Int(365.25 * X) + AstroMath.Int(30.6001 * (M + 1)) + D + 1722519 + β;
int c = AstroMath.Int((b - 122.1) / 365.25);
int d = AstroMath.Int(365.25 * c);
int e = AstroMath.Int((b - d) / 30.6001);
D = b - d - AstroMath.Int(30.6001 * e);
if (e < 14)
{
M = e - 1;
}
else
{
M = e - 13;
}
X = c - 4716;
int W = 2;
if (X % 4 == 0)
{
W = 1;
}
int N = AstroMath.Int((275 * M) / 9) - W * AstroMath.Int((M + 9) / 12) + D - 30;
int A = X - 623;
int B = AstroMath.Int(A / 4);
int C = A % 4;
double C1 = 365.2501 * C;
int C2 = AstroMath.Int(C1);
if (C1 - C2 > 0.5)
{
C2 = C2 + 1;
}
int D1 = (1461 * B) + 170 + C2;
int Q = AstroMath.Int(D1 / 10631);
int R = D1 % 10631;
int J = AstroMath.Int(R / 354);
int K = R % 354;
int O = AstroMath.Int(((11 * J) + 14) / 30);
int H = (30 * Q) + J + 1;
int JJ = K - O + N - 1;
int CL = H % 30;
int DL = ((11 * CL) + 3) % 30;
if (DL < 19)
{
JJ = JJ - 354;
H = H + 1;
}
if (DL > 18)
{
JJ = JJ - 355;
H = H + 1;
}
int S = AstroMath.Int((JJ - 1) / 29.5);
int m = 1 + S;
d = AstroMath.Int(JJ - (29.5 * S));
if (JJ == 355)
{
m = 12;
d = 30;
}
return(new IslamicCalendar(H, m, d));
}
