On Fri, 2 Feb 2001, Thomas Lockhart wrote:
> > I have written a function to calculate the julian day from any gregorian day.
> > You can include this code in the contrib directory or whatever place seems
> > applicable in future releases of posgresql.
>
> Looks nice!
>
> There is already a j2date()/date2j() subroutine pair in the backend, to
> support all of the existing date/time arithmetic. Would you be willing
> to use calls to that? Then we wouldn't have two sets of code to maintain
> (not that JD calculations change very often ;)
>
> It would likely be helpful to have a, say, "julian" argument to
> date_part(), which I'd be happy to add in. There is already access to
> Julian date using the to_char(date,'J') function call, and you can get a
> numeric type return using
>
> cast(to_char(date,'J') as int)
... and vice versa:
test=# select to_timestamp('2451946', 'J');
to_timestamp
------------------------
2001-02-05 00:00:00+01
(1 row)
Karel