Version: (using KDE KDE 3.2.1) OS: Linux Planck uses a time reference called AIT which starts on January 1st 1958 (please don't ask me why). The exact difference in seconds between UT and AIT is 86400L * (365*12 + 3) - 32 (seconds) Could you please add this time reference to the list ?
Is this some kind of standard, or something only known within Planck? -----Original Message----- From: Marc-Antoine Miville-Deschenes [mailto:mamd@cita.utoronto.ca] Sent: Thursday, October 21, 2004 5:53 AM To: kst@kde.org Subject: [Kst] [Bug 91823] New: time convention for Planck ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. http://bugs.kde.org/show_bug.cgi?id=91823 Summary: time convention for Planck Product: kst Version: unspecified Platform: unspecified OS/Version: Linux Status: NEW Severity: wishlist Priority: NOR Component: general AssignedTo: kst kde org ReportedBy: mamd cita utoronto ca Version: (using KDE KDE 3.2.1) OS: Linux Planck uses a time reference called AIT which starts on January 1st 1958 (please don't ask me why). The exact difference in seconds between UT and AIT is 86400L * (365*12 + 3) - 32 (seconds) Could you please add this time reference to the list ? _______________________________________________ Kst mailing list Kst@kde.org https://mail.kde.org/mailman/listinfo/kst
Added AIT to list of understood time formats.
This is to correct little errors I made in the definition of the Planck reference time (so-called AIT). In fact it is a general standard named TAI (for Temps Atomique International) based on an atomic clock in Paris. There is not a direct transformation from UTC to TAI as some "leap seconds" are added periodically to the UTC (because of the earth precession). Nowadays the relation is TAI = UTC + 32 seconds (and not UTC-32 seconds as I said previously). So, this is to suggest 2) Modify name of the conversion (the official name is TAI) 1) Correct transformation (TAI = UTC + 32 seconds)
CVS commit by arwalker: Correctly identify the TAI time standard. CCMAIL: 91823-done@bugs.kde.org M +7 -1 kst2dplot.cpp 1.352 M +1 -1 kstplotdefines.h 1.8 --- kdeextragear-2/kst/kst/kst2dplot.cpp #1.351:1.352 @@ -1282,5 +1282,11 @@ double Kst2DPlot::convertTimeValueToJD(d break; case X_AXIS_INTERP_AIT: - value -= 86400.0 * (365.0 * 12.0 + 3.0) - 32.0; // difference (seconds) between standard C time and AIT + value -= 86400.0 * (365.0 * 12.0 + 3.0); + // + // current difference (seconds) between standard C time and AIT + // refer to the following for more information: + // http://hpiers.obspm.fr/eop-pc/earthor/utc/TAI-UTC_tab.html + // + value -= 32.0; value /= 24.0 * 60.0 * 60.0; value += JD1970; --- kdeextragear-2/kst/kst/kstplotdefines.h #1.7:1.8 @@ -58,5 +58,5 @@ const XAxisInterpretation XAxisInterpret { I18N_NOOP2("Modified Julian Date", "MJD"), X_AXIS_INTERP_MJD }, { I18N_NOOP2("Reduced Julian Date", "RJD"), X_AXIS_INTERP_RJD }, - { I18N_NOOP2("Time format specific to Planck project", "AIT (Planck)"), X_AXIS_INTERP_AIT } + { I18N_NOOP2("Temps Atomique International", "TAI"), X_AXIS_INTERP_AIT } };