Genya>
SOMETIMES shows parameters used GMT
It might be related with "user.timezone" Java property.
I would either recommend using Java 8's java.time API (it has notion for timestamp+timezone) or use setTimestamp(.., Timestamp, Calendar).
There's PGTimestamp, however it is not much better than java.time.
In case of "setTimestamp(3, Timestamp)" the value that is sent to the DB depends on the Java's default time zone.
Would you please check that?