Ju24da.cin

Ju24da.cin is pair of the C++ routines to evaluate the Short Julian day from date and back

Code

void ju24da(int Mjd, int *Year, int *Month, int *Day)
{ int J, C, Y, M;
    J = Mjd + 2400000 + 68569;
// J = Mjd + 2400001 + 68569;
// J = Mjd + 68569;
    C = 4 * J / 146097;
    J = J - (146097 * C + 3) / 4;
    Y = 4000 * (J + 1) / 1461001;
    J = J - 1461 * Y / 4 + 31;
    M = 80 * J / 2447;
    *Day = J - 2447 * M / 80;
    J = M / 11;
    *Month = M + 2 - (12 * J);
    *Year = 100 * (C - 49) + Y + J;
// http://www.leapsecond.com/tools/gpsdate.c
}

int daju24(int Y,int M, int D)
{ int a, y,m;
  a=(14-M)/12;
  y=Y+4800-a;
  m=M+12*a-3;
// return D + (153*m+2)/5 +365*y + y/4 - y/100 + y/400 -32045 - 2400001;
  return D + (153*m+2)/5 +365*y + y/4 - y/100 + y/400 -32045 - 2400000;
}

References

Keywords

Short Julian day