jdcalf¶

erfa.jdcalf(ndp, dj1, dj2)[source]¶

Julian Date to Gregorian Calendar, expressed in a form convenient for formatting messages: rounded to a specified precision.

Parameters:

ndpint array
dj1double array
dj2double array

Returns:

iymdfint array

Notes

Wraps ERFA function eraJdcalf. The ERFA documentation is:

- - - - - - - - - -
 e r a J d c a l f
- - - - - - - - - -

Julian Date to Gregorian Calendar, expressed in a form convenient
for formatting messages:  rounded to a specified precision.

Given:
   ndp       int      number of decimal places of days in fraction
   dj1,dj2   double   dj1+dj2 = Julian Date (Note 1)

Returned:
   iymdf     int[4]   year, month, day, fraction in Gregorian
                      calendar

Returned (function value):
             int      status:
                        -1 = date out of range
                         0 = OK
                        +1 = ndp not 0-9 (interpreted as 0)

Notes:

1) The Julian Date is apportioned in any convenient way between
   the arguments dj1 and dj2.  For example, JD=2450123.7 could
   be expressed in any of these ways, among others:

           dj1            dj2

       2450123.7           0.0       (JD method)
       2451545.0       -1421.3       (J2000 method)
       2400000.5       50123.2       (MJD method)
       2450123.5           0.2       (date & time method)

2) In early eras the conversion is from the "Proleptic Gregorian
   Calendar";  no account is taken of the date(s) of adoption of
   the Gregorian Calendar, nor is the AD/BC numbering convention
   observed.

3) See also the function eraJd2cal.

4) The number of decimal places ndp should be 4 or less if internal
   overflows are to be avoided on platforms which use 16-bit
   integers.

Called:
   eraJd2cal    JD to Gregorian calendar

Reference:

   Explanatory Supplement to the Astronomical Almanac,
   P. Kenneth Seidelmann (ed), University Science Books (1992),
   Section 12.92 (p604).

This revision:  2023 January 16

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

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jdcalf¶