Extracting the time zone from oracle.sql.TIMESTAMPTZ

I'm trying to figure out how to get the time zone information from an oracle.sql.TIMESTAMPTZ object. According to Oracle's Javadocs, the getBytes() method returns an array of 13 bytes, the last two of which specify the time zone -- but all it has to say about *how* the time zone is represented in those two bytes is "The timezone information is stored as an offset in the RegionID format or in the HOUR/MINUTE format". No mention what RegionID format is.

Looking at the TIMESTAMPTZ object returned by the query "select current_timestamp from dual", casting the ResultSet to OracleResultSet, and calling getTIMESTAMPTZ(), I got the value 5436 (or 153C hex, with 15 being at index 11 and 3C at index 12 in the byte array). This value does not look like it's hours/minutes, so I assume it's a RegionID. BTW, I am in the Central European Time Zone (Netherlands/Amsterdam), which is UTC+0100.

I don't know how to convert this RegionID value to a time zone ID as recognized by the Java TimeZone class. And, the only way I have come up with so far for getting any timezone information at all from TIMESTAMPTZ is to call timestampValue(), and then use the getTimezoneOffset() method on the java.sql.Timestamp object. There are two things wrong with that approach: getTimezoneOffset() is a deprecated method, and: the value it returns is just an offset in minutes, not a timezone ID, so I wouldn't be able to distinguish between CET and any number of African time zones, for instance.

Thanks for any insights or pointers!

• Thomas