Hibernate and MySQL: UTC datetime - mysql

Question

We have a MySQL database where UTC timestamps are persisted into a DATETIME column.
I am retrieving these times via Hibernate (into a Date property, with TemporalType.TIMESTAMP) and wish to display them to the user unchanged.
The issue I am seeing is that when Hibernate reads the column value, it assigns a timezone (seconds from epoch) value to the object's Date property. However, it is storing this value as per the local time zone.
mysql> create table datetest(mydate datetime);
Query OK, 0 rows affected (0.13 sec)
mysql> insert into datetest values('2012-07-25 16:00:00');
Query OK, 1 row affected (0.00 sec)
mysql> select mydate from datetest;
+---------------------+
| mydate |
+---------------------+
| 2012-07-25 16:00:00 |
+---------------------+
1 row in set (0.00 sec)
Loading the "datetest" object within Hibernate and viewing the "mydate" value shows the value as:
2012-05-24T15:00:00.000+0100
I am in the UK, so +0100 (GMT+DST) is the local timezone. This matches the UNIX_TIMESTAMP() result:
mysql> select unix_timestamp(mydate) from datetest;
+------------------------+
| unix_timestamp(mydate) |
+------------------------+
| 1343228400 |
+------------------------+
1 row in set (0.00 sec)
I presume that when Hibernate loads the record it uses UNIX_TIMESTAMP() to populate the Date property of the object. The documentation for UNIX_TIMESTAMP() states:
The server interprets date as a value in the current time zone and
converts it to an internal value in UTC
I do not have control to change the server's time zone globally, and there are many other timezone related columns in our database which should not change. So how can I tell Hibernate that only some column values are UTC and ensure it does not apply any timezone 'formatting' to them ?
Within the MySQL command line client I can change the local timezone using
SET TIME_ZONE='+0:00'
And this allows UNIX_TIMESTAMP() to return a UTC value, but I cannot work out how to tell Hibernate to send this value before running the Criteria/Projection that extracts the information from the database..

Answer 1

A Java Timestamp doesn't have any time zone. The time zone you see is your local time zone, which is displayed by the method which transforms the Timestamp instance into a readable String (and that you've not told us in your question). And for your convenience, this method seems to use your local time zone, in order for you to be able to easily compare the time it displays with the time displayed by your wall clock.
If you want to format the Timestamp instance in another way, using another time zone, use SimpleDateFormat.