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#include "erfa.h"
int eraCal2jd(int iy, int im, int id, double *djm0, double *djm)
/*
** - - - - - - - - - -
** e r a C a l 2 j d
** - - - - - - - - - -
**
** Gregorian Calendar to Julian Date.
**
** 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 ERFA
** 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).
**
** Copyright (C) 2013-2014, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
int j, ly, my;
long iypmy;
/* Earliest year allowed (4800BC) */
const int IYMIN = -4799;
/* Month lengths in days */
static 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 = ERFA_DJM0;
*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) 2013-2014, NumFOCUS Foundation.
** All rights reserved.
**
** This library is derived, with permission, from the International
** Astronomical Union's "Standards of Fundamental Astronomy" library,
** available from http://www.iausofa.org.
**
** The ERFA version is intended to retain identical functionality to
** the SOFA library, but made distinct through different function and
** file names, as set out in the SOFA license conditions. The SOFA
** original has a role as a reference standard for the IAU and IERS,
** and consequently redistribution is permitted only in its unaltered
** state. The ERFA version is not subject to this restriction and
** therefore can be included in distributions which do not support the
** concept of "read only" software.
**
** Although the intent is to replicate the SOFA API (other than
** replacement of prefix names) and results (with the exception of
** bugs; any that are discovered will be fixed), SOFA is not
** responsible for any errors found in this version of the library.
**
** If you wish to acknowledge the SOFA heritage, please acknowledge
** that you are using a library derived from SOFA, rather than SOFA
** itself.
**
**
** TERMS AND CONDITIONS
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1 Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
**
** 2 Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
**
** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
** the International Astronomical Union nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
** POSSIBILITY OF SUCH DAMAGE.
**
*/
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