Re: Can `format-time-string' produce full/extended ISO 8601 times?

[Juri Linkov <juri@jurta.org>]

> To reiterate, the gist of my query is this:
>
>   Is it possible to format the UTC offset/ZONE with a colon per the
> 'Extended format?

I looked briefly at the implementation of time formatting in Emacs
and see that it is an old copy of the function `strftime' from gnulib.
I wonder is it possible to call this function directly from the library
where it already has more supported formats including time zones with
a colon:

`%z'
     RFC 2822/ISO 8601 style numeric time zone (e.g., `-0600' or
     `+0530'), or nothing if no time zone is determinable.
     This is a GNU extension.

`%:z'
     RFC 3339/ISO 8601 style numeric time zone with `:' (e.g., `-06:00'
     or `+05:30'), or nothing if no time zone is determinable.  This is
     a GNU extension.

`%::z'
     Numeric time zone to the nearest second with `:' (e.g.,
     `-06:00:00' or `+05:30:00'), or nothing if no time zone is
     determinable.  This is a GNU extension.

`%:::z'
     Numeric time zone with `:' using the minimum necessary precision
     (e.g., `-06', `+05:30', or `-04:56:02'), or nothing if no time
     zone is determinable.  This is a GNU extension.

-- 
Juri Linkov
http://www.jurta.org/emacs/