Timezones with minute and second offsets cause DateTime::Format::Pg to
throw an error and PostgreSQL will happily hand them out, accept them
back, and do proper time math with them.
Snippets from psql:
rbt=# set timezone = 'America/Toronto';
SET
rbt=# select '1894-01-01'::timestamp with time zone;
timestamptz
------------------------------
1894-01-01 00:00:00-05:17:32
(1 row)
rbt=# select '1894-01-01 00:00:00-05:17:32'::timestamp with time zone +
interval '100 years';
?column?
------------------------
1994-01-01 00:00:00-05
(1 row)
RT for rt.cpan.org