#include "sofam.h" int iauCal2jd(int iy, int im, int id, double *djm0, double *djm) /* ** - - - - - - - - - - ** i a u C a l 2 j d ** - - - - - - - - - - ** ** Gregorian Calendar to Julian Date. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: support function. ** ** Given: ** iy,im,id int year, month, day in Gregorian calendar (Note 1) ** ** Returned: ** djm0 double MJD zero-point: always 2400000.5 ** djm double Modified Julian Date for 0 hrs ** ** Returned (function value): ** int status: ** 0 = OK ** -1 = bad year (Note 3: JD not computed) ** -2 = bad month (JD not computed) ** -3 = bad day (JD computed) ** ** Notes: ** ** 1) The algorithm used is valid from -4800 March 1, but this ** implementation rejects dates before -4799 January 1. ** ** 2) The Julian Date is returned in two pieces, in the usual SOFA ** manner, which is designed to preserve time resolution. The ** Julian Date is available as a single number by adding djm0 and ** djm. ** ** 3) In early eras the conversion is from the "Proleptic Gregorian ** Calendar"; no account is taken of the date(s) of adoption of ** the Gregorian Calendar, nor is the AD/BC numbering convention ** observed. ** ** Reference: ** ** Explanatory Supplement to the Astronomical Almanac, ** P. Kenneth Seidelmann (ed), University Science Books (1992), ** Section 12.92 (p604). ** ** This revision: 2008 October 28 ** ** Copyright (C) 2008 IAU SOFA Review Board. See notes at end. */ { int j, ly, my; long iypmy; /* Earliest year allowed (4800BC) */ const int IYMIN = -4799; /* Month lengths in days */ const int mtab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; /* Preset status. */ j = 0; /* Validate year and month. */ if (iy < IYMIN) return -1; if (im < 1 || im > 12) return -2; /* If February in a leap year, 1, otherwise 0. */ ly = ((im == 2) && !(iy%4) && (iy%100 || !(iy%400))); /* Validate day, taking into account leap years. */ if ( (id < 1) || (id > (mtab[im-1] + ly))) j = -3; /* Return result. */ my = (im - 14) / 12; iypmy = (long) (iy + my); *djm0 = 2400000.5; *djm = (double)((1461L * (iypmy + 4800L)) / 4L + (367L * (long) (im - 2 - 12 * my)) / 12L - (3L * ((iypmy + 4900L) / 100L)) / 4L + (long) id - 2432076L); /* Return status. */ return j; /*----------------------------------------------------------------------- ** ** Copyright (C) 2008 ** Standards Of Fundamental Astronomy Review Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS ** WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Review Board ("the Board"). ** ** 2. Permission is granted to anyone to use the SOFA software for any ** purpose, including commercial applications, free of charge and ** without payment of royalties, subject to the conditions and ** restrictions listed below. ** ** 3. You (the user) may copy and adapt the SOFA software and its ** algorithms for your own purposes and you may copy and distribute ** a resulting "derived work" to others on a world-wide, royalty-free ** basis, provided that the derived work complies with the following ** requirements: ** ** a) Your work shall be marked or carry a statement that it (i) uses ** routines and computations derived by you from software provided ** by SOFA under license to you; and (ii) does not contain ** software provided by SOFA or software that has been distributed ** by or endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon and/or differs from the ** original SOFA software. ** ** c) The name(s) of all routine(s) that you distribute shall differ ** from the SOFA names, even when the SOFA content has not been ** otherwise changed. ** ** d) The routine-naming prefix "iau" shall not be used. ** ** e) The origin of the SOFA components of your derived work must not ** be misrepresented; you must not claim that you wrote the ** original software, nor file a patent application for SOFA ** software or algorithms embedded in the SOFA software. ** ** f) These requirements must be reproduced intact in any source ** distribution and shall apply to anyone to whom you have granted ** a further right to modify the source code of your derived work. ** ** 4. In any published work or commercial products which includes ** results achieved by using the SOFA software, you shall acknowledge ** that the SOFA software was used in obtaining those results. ** ** 5. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or by ** inappropriate modification. ** ** 6. The SOFA software is provided "as is" and the Board makes no ** warranty as to its use or performance. The Board does not and ** cannot warrant the performance or results which the user may obtain ** by using the SOFA software. The Board makes no warranties, express ** or implied, as to non-infringement of third party rights, ** merchantability, or fitness for any particular purpose. In no ** event will the Board be liable to the user for any consequential, ** incidental, or special damages, including any lost profits or lost ** savings, even if a Board representative has been advised of such ** damages, or for any claim by any third party. ** ** 7. The provision of any version of the SOFA software under the terms ** and conditions specified herein does not imply that future ** versions will also be made available under the same terms and ** conditions. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** Internet email: sofa@rl.ac.uk ** Postal address: IAU SOFA Center ** Rutherford Appleton Laboratory ** Chilton, Didcot, Oxon OX11 0QX ** United Kingdom ** **---------------------------------------------------------------------*/ }