DOUBLE PRECISION FUNCTION sla_DAT (UTC) *+ * - - - - * D A T * - - - - * * Increment to be applied to Coordinated Universal Time UTC to give * International Atomic Time TAI (double precision) * * Given: * UTC d UTC date as a modified JD (JD-2400000.5) * * Result: TAI-UTC in seconds * * Notes: * * 1 The UTC is specified to be a date rather than a time to indicate * that care needs to be taken not to specify an instant which lies * within a leap second. Though in most cases UTC can include the * fractional part, correct behaviour on the day of a leap second * can only be guaranteed up to the end of the second 23:59:59. * * 2 For epochs from 1961 January 1 onwards, the expressions from the * file ftp://maia.usno.navy.mil/ser7/tai-utc.dat are used. * * 3 The 5ms time step at 1961 January 1 is taken from 2.58.1 (p87) of * the 1992 Explanatory Supplement. * * 4 UTC began at 1960 January 1.0 (JD 2436934.5) and it is improper * to call the routine with an earlier epoch. However, if this * is attempted, the TAI-UTC expression for the year 1960 is used. * * * :-----------------------------------------: * : : * : IMPORTANT : * : : * : This routine must be updated on each : * : occasion that a leap second is : * : announced : * : : * : Latest leap second: 2016 December 31 : * : : * :-----------------------------------------: * * Last revision: 03 October 2016 * * Copyright P.T.Wallace. All rights reserved. * * License: * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (see SLA_CONDITIONS); if not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * *- IMPLICIT NONE DOUBLE PRECISION UTC DOUBLE PRECISION DT IF (.FALSE.) THEN * - - - - - - - - - - - - - - - - - - - - - - * * Add new code here on each occasion that a * * leap second is announced, and update the * * preamble comments appropriately. * * - - - - - - - - - - - - - - - - - - - - - - * * 2017 January 1 ELSE IF (UTC.GE.57754D0) THEN DT=37D0 * 2015 July 1 ELSE IF (UTC.GE.57204D0) THEN DT=36D0 * 2012 July 1 ELSE IF (UTC.GE.56109D0) THEN DT=35D0 * 2009 January 1 ELSE IF (UTC.GE.54832D0) THEN DT=34D0 * 2006 January 1 ELSE IF (UTC.GE.53736D0) THEN DT=33D0 * 1999 January 1 ELSE IF (UTC.GE.51179D0) THEN DT=32D0 * 1997 July 1 ELSE IF (UTC.GE.50630D0) THEN DT=31D0 * 1996 January 1 ELSE IF (UTC.GE.50083D0) THEN DT=30D0 * 1994 July 1 ELSE IF (UTC.GE.49534D0) THEN DT=29D0 * 1993 July 1 ELSE IF (UTC.GE.49169D0) THEN DT=28D0 * 1992 July 1 ELSE IF (UTC.GE.48804D0) THEN DT=27D0 * 1991 January 1 ELSE IF (UTC.GE.48257D0) THEN DT=26D0 * 1990 January 1 ELSE IF (UTC.GE.47892D0) THEN DT=25D0 * 1988 January 1 ELSE IF (UTC.GE.47161D0) THEN DT=24D0 * 1985 July 1 ELSE IF (UTC.GE.46247D0) THEN DT=23D0 * 1983 July 1 ELSE IF (UTC.GE.45516D0) THEN DT=22D0 * 1982 July 1 ELSE IF (UTC.GE.45151D0) THEN DT=21D0 * 1981 July 1 ELSE IF (UTC.GE.44786D0) THEN DT=20D0 * 1980 January 1 ELSE IF (UTC.GE.44239D0) THEN DT=19D0 * 1979 January 1 ELSE IF (UTC.GE.43874D0) THEN DT=18D0 * 1978 January 1 ELSE IF (UTC.GE.43509D0) THEN DT=17D0 * 1977 January 1 ELSE IF (UTC.GE.43144D0) THEN DT=16D0 * 1976 January 1 ELSE IF (UTC.GE.42778D0) THEN DT=15D0 * 1975 January 1 ELSE IF (UTC.GE.42413D0) THEN DT=14D0 * 1974 January 1 ELSE IF (UTC.GE.42048D0) THEN DT=13D0 * 1973 January 1 ELSE IF (UTC.GE.41683D0) THEN DT=12D0 * 1972 July 1 ELSE IF (UTC.GE.41499D0) THEN DT=11D0 * 1972 January 1 ELSE IF (UTC.GE.41317D0) THEN DT=10D0 * 1968 February 1 ELSE IF (UTC.GE.39887D0) THEN DT=4.2131700D0+(UTC-39126D0)*0.002592D0 * 1966 January 1 ELSE IF (UTC.GE.39126D0) THEN DT=4.3131700D0+(UTC-39126D0)*0.002592D0 * 1965 September 1 ELSE IF (UTC.GE.39004D0) THEN DT=3.8401300D0+(UTC-38761D0)*0.001296D0 * 1965 July 1 ELSE IF (UTC.GE.38942D0) THEN DT=3.7401300D0+(UTC-38761D0)*0.001296D0 * 1965 March 1 ELSE IF (UTC.GE.38820D0) THEN DT=3.6401300D0+(UTC-38761D0)*0.001296D0 * 1965 January 1 ELSE IF (UTC.GE.38761D0) THEN DT=3.5401300D0+(UTC-38761D0)*0.001296D0 * 1964 September 1 ELSE IF (UTC.GE.38639D0) THEN DT=3.4401300D0+(UTC-38761D0)*0.001296D0 * 1964 April 1 ELSE IF (UTC.GE.38486D0) THEN DT=3.3401300D0+(UTC-38761D0)*0.001296D0 * 1964 January 1 ELSE IF (UTC.GE.38395D0) THEN DT=3.2401300D0+(UTC-38761D0)*0.001296D0 * 1963 November 1 ELSE IF (UTC.GE.38334D0) THEN DT=1.9458580D0+(UTC-37665D0)*0.0011232D0 * 1962 January 1 ELSE IF (UTC.GE.37665D0) THEN DT=1.8458580D0+(UTC-37665D0)*0.0011232D0 * 1961 August 1 ELSE IF (UTC.GE.37512D0) THEN DT=1.3728180D0+(UTC-37300D0)*0.001296D0 * 1961 January 1 ELSE IF (UTC.GE.37300D0) THEN DT=1.4228180D0+(UTC-37300D0)*0.001296D0 * Before that ELSE DT=1.4178180D0+(UTC-37300D0)*0.001296D0 END IF sla_DAT=DT END