timeconvert.h

Header file for time conversion functions.

Author

Rahil Makadia makadia2@illinois.edu

LICENSE

Copyright (C) 2022-2025 Rahil Makadia

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 3 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; if not, see https://www.gnu.org/licenses.

Functions

void jd_to_et(const real jd, real &et)

Convert Julian Date to TDB ephemeris time.

Parameters:

• jd – [in] Julian Date.

• et – [out] TDB ephemeris time.

real jd_to_et(const real jd)

Convert Julian Date to TDB ephemeris time.

Parameters:

jd – [in] Julian Date.

Returns:

real TDB ephemeris time.

void jd_to_mjd(const real jd, real &mjd)

Convert Julian Date to Modified Julian Date.

Parameters:

• jd – [in] Julian Date.

• mjd – [out] Modified Julian Date.

real jd_to_mjd(const real jd)

Convert Julian Date to Modified Julian Date.

Parameters:

jd – [in] Julian Date.

Returns:

real Modified Julian Date.

void et_to_jd(const real et, real &jd)

Convert TDB ephemeris time to Julian Date.

Parameters:

• et – [in] TDB ephemeris time.

• jd – [out] Julian Date.

real et_to_jd(const real et)

Convert TDB ephemeris time to Julian Date.

Parameters:

et – [in] TDB ephemeris time.

Returns:

real Julian Date.

void et_to_mjd(const real et, real &mjd)

Convert TDB ephemeris time to Modified Julian Date.

Parameters:

• et – [in] TDB ephemeris time.

• mjd – [out] Modified Julian Date.

real et_to_mjd(const real et)

Convert TDB ephemeris time to Modified Julian Date.

Parameters:

et – [in] TDB ephemeris time.

Returns:

real Modified Julian Date.

void mjd_to_jd(const real mjd, real &jd)

Convert Modified Julian Date to Julian Date.

Parameters:

• mjd – [in] Modified Julian Date.

• jd – [out] Julian Date.

real mjd_to_jd(const real mjd)

Convert Modified Julian Date to Julian Date.

Parameters:

mjd – [in] Modified Julian Date.

Returns:

real Julian Date.

void mjd_to_et(const real mjd, real &et)

Convert Modified Julian Date to TDB ephemeris time.

Parameters:

• mjd – [in] Modified Julian Date.

• et – [out] TDB ephemeris time.

real mjd_to_et(const real mjd)

Convert Modified Julian Date to TDB ephemeris time.

Parameters:

mjd – [in] Modified Julian Date.

Returns:

real TDB ephemeris time.

real delta_at_utc(const real mjdUtc)

Compute TAI-UTC difference in seconds at a given UTC Modified Julian Date.

Parameters:

mjdUtc – [in] UTC Modified Julian Date.

Returns:

real TAI-UTC.

real delta_at_tai(const real mjdTai)

Compute TAI-UTC difference in seconds at a given TAI Modified Julian Date.

Parameters:

mjdTai – [in] TAI Modified Julian Date.

Returns:

real TAI-UTC.

real delta_et_utc(const real mjdUtc)

Compute TDB-UTC difference in seconds at a given UTC Modified Julian Date.

Parameters:

mjdUtc – [in] UTC Modified Julian Date.

Returns:

real TDB-UTC.

real delta_et_tdb(const real mjdTdb)

Compute TDB-UTC difference in seconds at a given TDB Modified Julian Date.

Parameters:

mjdTdb – [in] TDB Modified Julian Date.

Returns:

real TDB-UTC.