erfa.epj(dj1, dj2)[source]

Julian Date to Julian Epoch.

dj1double array
dj2double array
c_retvaldouble array


Wraps ERFA function eraEpj. The ERFA documentation is:

- - - - - - -
 e r a E p j
- - - - - - -

Julian Date to Julian Epoch.

   dj1,dj2    double     Julian Date (Note 4)

Returned (function value):
              double     Julian Epoch


1) Julian Epoch is a method of expressing a moment in time as a
   year plus fraction.

2) Julian Epoch J2000.0 is 2000 Jan 1.5, and the length of the year
   is 365.25 days.

3) For historical reasons, the time scale formally associated with
   Julian Epoch is TDB (or TT, near enough).  However, Julian Epoch
   can be used more generally as a calendrical convention to
   represent other time scales such as TAI and TCB.  This is
   analogous to Julian Date, which was originally defined
   specifically as a way of representing Universal Times but is now
   routinely used for any of the regular time scales.

4) The Julian Date is supplied in two pieces, in the usual ERFA
   manner, which is designed to preserve time resolution.  The
   Julian Date is available as a single number by adding dj1 and
   dj2.  The maximum resolution is achieved if dj1 is 2451545.0


   Lieske, J.H., 1979, Astron.Astrophys. 73, 282.

This revision:  2022 May 6

Copyright (C) 2013-2023, NumFOCUS Foundation.
Derived, with permission, from the SOFA library.  See notes at end of file.