SUBROUTINE iau_JDCALF ( NDP, DJ1, DJ2, IYMDF, J ) *+ * - - - - - - - - - - - * i a u _ J D C A L F * - - - - - - - - - - - * * Julian Date to Gregorian Calendar, expressed in a form convenient * for formatting messages: rounded to a specified precision, and with * the fields stored in a single array. * * This routine is part of the International Astronomical Union's * SOFA (Standards of Fundamental Astronomy) software collection. * * Status: support routine. * * Given: * NDP i number of decimal places of days in fraction * DJ1,DJ2 d DJ1+DJ2 = Julian Date (Note 1) * * Returned: * IYMDF i(4) year, month, day, fraction in Gregorian * calendar * J i status: * -1 = date out of range * 0 = OK * +1 = NDP not 0-9 (interpreted as 0) * * Notes: * * 1) The Julian Date is apportioned in any convenient way between * the arguments DJ1 and DJ2. For example, JD=2450123.7 could * be expressed in any of these ways, among others: * * DJ1 DJ2 * * 2450123.7D0 0D0 (JD method) * 2451545D0 -1421.3D0 (J2000 method) * 2400000.5D0 50123.2D0 (MJD method) * 2450123.5D0 0.2D0 (date & time method) * * 2) 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. * * 3) Refer to the routine iau_JD2CAL. * * 4) NDP should be 4 or less if internal overflows are to be * avoided on machines which use 16-bit integers. * * Reference: * * Explanatory Supplement to the Astronomical Almanac, * P.Kenneth Seidelmann (ed), University Science Books (1992), * Section 12.92 (p604). * * Called: * iau_JD2CAL JD to Gregorian calendar * * This revision: 2001 January 4 * * Copyright (C) 2001 IAU SOFA Review Board. See notes at end. * *----------------------------------------------------------------------- IMPLICIT NONE INTEGER NDP DOUBLE PRECISION DJ1, DJ2 INTEGER IYMDF(4), J INTEGER JS DOUBLE PRECISION DENOM, D1, D2, F1, F2, F * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * Denominator of fraction (e.g. 100 for 2 decimal places). IF ( NDP.GE.0 .AND. NDP.LE.9 ) THEN DENOM = DBLE(10**NDP) ELSE J = 1 DENOM = 1D0 END IF * Copy the date, big then small, and realign to midnight. IF ( DJ1 .GE. DJ2 ) THEN D1 = DJ1 D2 = DJ2 ELSE D1 = DJ2 D2 = DJ1 END IF D2 = D2 - 0.5D0 * Separate days and fractions. F1 = MOD(D1,1D0) F2 = MOD(D2,1D0) D1 = ANINT(D1-F1) D2 = ANINT(D2-F2) * Round the total fraction to the specified number of places. F = ANINT(( F1+F2 ) * DENOM) / DENOM * Re-assemble the rounded date and re-align to noon. D2 = D2 + F + 0.5D0 * Convert to Gregorian Calendar. CALL iau_JD2CAL ( D1, D2, IYMDF(1), IYMDF(2), IYMDF(3), F, JS ) IF ( JS .EQ. 0 ) THEN IYMDF(4) = NINT(F*DENOM) ELSE J = JS END IF * Finished. *+---------------------------------------------------------------------- * * Copyright (C) 2001 * 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. The Software is made available free of charge for use by: * * a) private individuals for non-profit research; and * * b) non-profit educational, academic and research institutions. * * 3. Commercial use of the Software is specifically excluded from the * terms and conditions of this license. Commercial use of the * Software is subject to the prior written agreement of the Board on * terms to be agreed. * * 4. The provision of any version of the 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. * * 5. The user may modify the Software for his/her own purposes. The * user may distribute the modified software provided that the Board * is informed and that a copy of the modified software is made * available to the Board on request. All modifications made by the * user shall be clearly identified to show how the modified software * differs from the original Software, and the name(s) of the * affected routine(s) shall be changed. The original SOFA Software * License text must be present. * * 6. In any published work produced by the user and which includes * results achieved by using the Software, the user shall acknowledge * that the Software was used in producing the information contained * in such publication. * * 7. The user may incorporate or embed the Software into other software * products which he/she may then give away free of charge but not * sell provided the user makes due acknowledgement of the use which * he/she has made of the Software in creating such software * products. Any redistribution of the Software in this way shall be * made under the same terms and conditions under which the user * received it from the SOFA Center. * * 8. The user shall not cause the Software to be brought into * disrepute, either by misuse, or use for inappropriate tasks, or by * inappropriate modification. * * 9. The Software is provided to the user "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 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. * * 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 * * *----------------------------------------------------------------------- END