SUBROUTINE iau_DTF2D ( SCALE, IY, IM, ID, IHR, IMN, SEC, : D1, D2, J ) *+ * - - - - - - - - - - * i a u _ D T F 2 D * - - - - - - - - - - * * Encode date and time fields into 2-part Julian Date (or in the case * of UTC a quasi-JD form that includes special provision for leap * seconds). * * This routine is part of the International Astronomical Union's * SOFA (Standards of Fundamental Astronomy) software collection. * * Status: support routine. * * Given: * SCALE c*(*) time scale ID (Note 1) * IY,IM,ID i year, month, day in Gregorian calendar (Note 2) * IHR,IMN i hour, minute * SEC d seconds * * Returned: * D1,D2 d 2-part Julian Date (Notes 3,4) * J i status: +3 = both of next two * +2 = time is after end of day (Note 5) * +1 = dubious year (Note 6) * 0 = OK * -1 = bad year * -2 = bad month * -3 = bad day * -4 = bad hour * -5 = bad minute * -6 = bad second (<0) * * Notes: * * 1) SCALE identifies the time scale. Only the value 'UTC' (in upper * case) is significant, and enables handling of leap seconds (see * Note 4). * * 2) For calendar conventions and limitations, see iau_CAL2JD. * * 3) The sum of the results, D1+D2, is Julian Date, where normally D1 * is the Julian Day Number and D2 is the fraction of a day. In the * case of UTC, where the use of JD is problematical, special * conventions apply: see the next note. * * 4) JD cannot unambiguously represent UTC during a leap second unless * special measures are taken. The SOFA internal convention is that * the quasi-JD day represents UTC days whether the length is 86399, * 86400 or 86401 SI seconds. In the 1960-1972 era there were * smaller jumps (in either direction) each time the linear UTC(TAI) * expression was changed, and these "mini-leaps" are also included * in the SOFA convention. * * 5) The warning status "time is after end of day" usually means that * the SEC argument is greater than 60D0. However, in a day ending * in a leap second the limit changes to 61D0 (or 59D0 in the case of * a negative leap second). * * 6) The warning status "dubious year" flags UTCs that predate the * introduction of the time scale or that are too far in the future * to be trusted. See iau_DAT for further details. * * 7) Only in the case of continuous and regular time scales (TAI, TT, * TCG, TCB and TDB) is the result D1+D2 a Julian Date, strictly * speaking. In the other cases (UT1 and UTC) the result must be * used with circumspection; in particular the difference between * two such results cannot be interpreted as a precise time * interval. * * Called: * iau_CAL2JD Gregorian calendar to JD * iau_DAT delta(AT) = TAI-UTC * iau_JD2CAL JD to Gregorian calendar * * This revision: 2013 July 26 * * SOFA release 2021-01-25 * * Copyright (C) 2021 IAU SOFA Board. See notes at end. * *----------------------------------------------------------------------- IMPLICIT NONE CHARACTER*(*) SCALE INTEGER IY, IM, ID, IHR, IMN DOUBLE PRECISION SEC, D1, D2 INTEGER J * Days to seconds DOUBLE PRECISION D2S PARAMETER ( D2S = 86400D0 ) INTEGER JS, IY2, IM2, ID2 DOUBLE PRECISION DJ, W, DAY, SECLIM, DAT0, DAT12, DAT24, : DLEAP, TIME * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * Today's Julian Day Number. CALL iau_CAL2JD ( IY, IM, ID, DJ, W, JS ) IF ( JS.NE.0 ) GO TO 9 DJ = DJ + W * Day length and final minute length in seconds (provisional). DAY = D2S SECLIM = 60D0 * Deal with the UTC leap second case. IF ( SCALE.EQ.'UTC' ) THEN * TAI-UTC at 0h today. CALL iau_DAT ( IY, IM, ID, 0D0, DAT0, JS ) IF ( JS.LT.0 ) GO TO 9 * TAI-UTC at 12h today (to detect drift). CALL iau_DAT ( IY, IM, ID, 0.5D0, DAT12, JS ) IF ( JS.LT.0 ) GO TO 9 * TAI-UTC at 0h tomorrow (to detect jumps). CALL iau_JD2CAL ( DJ, 1.5D0, IY2, IM2, ID2, W, JS ) IF ( JS.NE.0 ) GO TO 9 CALL iau_DAT ( IY2, IM2, ID2, 0D0, DAT24, JS ) IF ( JS.LT.0 ) GO TO 9 * Any sudden change in TAI-UTC between today and tomorrow. DLEAP = DAT24 - ( 2D0 * DAT12 - DAT0 ) * If leap second day, correct the day and final minute lengths. DAY = DAY + DLEAP IF ( IHR.EQ.23 .AND. IMN.EQ.59 ) SECLIM = SECLIM + DLEAP * End of UTC-specific actions. END IF * Validate the time. IF ( IHR.GE.0 .AND. IHR.LE.23 ) THEN IF ( IMN.GE.0 .AND. IMN.LE.59 ) THEN IF ( SEC.GE.0D0 ) THEN IF ( SEC.GE.SECLIM ) THEN JS = JS + 2 END IF ELSE JS = -6 END IF ELSE JS = -5 END IF ELSE JS = -4 END IF IF ( JS.LT.0 ) GO TO 9 * The time in days. TIME = (60D0*DBLE(60*IHR+IMN)+SEC) / DAY * Return the date and time. D1 = DJ D2 = TIME * Return the status. 9 CONTINUE J = JS * Finished. *+---------------------------------------------------------------------- * * Copyright (C) 2021 * Standards Of Fundamental Astronomy Board * of the International Astronomical Union. * * ===================== * SOFA Software License * ===================== * * NOTICE TO USER: * * BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND * CONDITIONS WHICH APPLY TO ITS USE. * * 1. The Software is owned by the IAU SOFA Board ("SOFA"). * * 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 distribute SOFA source code to others, * and use and adapt its code and algorithms in your own software, * on a world-wide, royalty-free basis. That portion of your * distribution that does not consist of intact and unchanged copies * of SOFA source code files is a "derived work" that must comply * 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 itself constitute software provided by and/or * endorsed by SOFA. * * b) The source code of your derived work must contain descriptions * of how the derived work is based upon, contains and/or differs * from the original SOFA software. * * c) The names of all routines in your derived work shall not * include the prefix "iau" or "sofa" or trivial modifications * thereof such as changes of case. * * d) 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. * * e) 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. * * Note that, as originally distributed, the SOFA software is * intended to be a definitive implementation of the IAU standards, * and consequently third-party modifications are discouraged. All * variations, no matter how minor, must be explicitly marked as * such, as explained above. * * 4. You shall not cause the SOFA software to be brought into * disrepute, either by misuse, or use for inappropriate tasks, or * by inappropriate modification. * * 5. The SOFA software is provided "as is" and SOFA makes no warranty * as to its use or performance. SOFA does not and cannot warrant * the performance or results which the user may obtain by using the * SOFA software. SOFA 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 SOFA be * liable to the user for any consequential, incidental, or special * damages, including any lost profits or lost savings, even if a * SOFA representative has been advised of such damages, or for any * claim by any third party. * * 6. 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. * * In any published work or commercial product which uses the SOFA * software directly, acknowledgement (see www.iausofa.org) is * appreciated. * * Correspondence concerning SOFA software should be addressed as * follows: * * By email: sofa@ukho.gov.uk * By post: IAU SOFA Center * HM Nautical Almanac Office * UK Hydrographic Office * Admiralty Way, Taunton * Somerset, TA1 2DN * United Kingdom * *----------------------------------------------------------------------- END