Robert,
The driver certainly doesn't do anything to a statement like
insert into foo (datecol) values (now())
it does use the calendar of the vm to get the string representation.
Time, and date are two things not very well handled in java or JDBC. What is the exact column type and what does it store in the database
But to answer your question you can do:
stmt.setTimestamp(1, t, Calendar.getInstance( TimeZone.getTimeZone("UTC")))