Postgres RFC3339 datetime formatting

Is there any way to format datetime to RFC3339Nano Eg:
2006-01-02T15:04:05.999999999Z07:00 in postgres 9.3 or 9.5?

I tried with to_char. But there is no documentation how to handle T, Z,
+07:00, -07:00 etc.

The nearest one I can reach is

v2=# select to_char(current_timestamp, 'YYYY-MM-DD HH:MI:SS.MSOF');
to_char----------------------------
2016-05-08 12:16:14.493+04

Which is default JSON output format datetime in postgres 9.3. Please see
below.

psql (9.5.1, server 9.3.6)
Type "help" for help.

fetchrdb=> select to_json(current_timestamp);
to_json---------------------------------
"2016-05-08 11:58:04.844548+04"(1 row)

In the case of JSON encoded output from postgres 9.5 is RFC3339Nano eg:

psql (9.5.1)
Type "help" for help.

v2=# select to_json(current_timestamp);
to_json------------------------------------
"2016-05-08T11:59:17.121411+04:00"

I could't find an option to format datetime to RFC3339Nano in postgres 9.3
or 9.5 using to_char.

http://www.postgresql.org/docs/9.5/static/functions-formatting.html

Is there any hidden option/functions you use to achieve the same? Any help
regarding is appreciated.

--
Thanks & Regards
skype: jasim.mk