Timezone error when casting. Maybe daylight saving

I try to build with the tests, but when I run the test
org.postgresql.test.jdbc2.StatementTest.testDateFunctions() i get:
junit.framework.AssertionFailedError: expected:<-3> but was:<-2>

When I run the same function directly in PostgreSQL, I also get -2:

test=> select extract( day from ((CAST(-3 || ' day' as
interval)+now())-now()));
date_part
-----------
-2

When I remove the extract day from the expression, I get:
test=> select CAST(-3 || ' day' as interval)+now()-now();
?column?
-------------------
-2 days -23:00:00

Also note these two:

test=> select '3 day'::interval + now();
?column?
-------------------------------
2014-04-04 22:13:36.144756+02

test=> select (CAST(-3 || ' days' as interval)+now());
?column?
-------------------------------
2014-03-29 22:13:38.880739+01

Which should give the same timezone, but they are in +01 and +02.

This seems like a timezone problem, but I do not yet fully understand
why. My timezone is "Europe/Oslo". My PostgreSQL version is 9.3.4, from
PostgreSQL's YUM-repo.

PS: I sent this to both bugs and pgjdbc as it is a bug in PostgreSQL and
affects pgjdbc.

Regards,

Kjetil Nygård
Phone: +47 41 47 43 37