Oracle has reversed a decision it made to remove the "tzupdater" tool from public download. The tool is used to update Java's internal time zone database and allows users to adjust Java installations so they reflect correct timezones from around the world. Oracle had decided to remove the "tzupdater" tool at the start of March as part of the company's ending of public updates to Oracle JDK 6, only making the software available to customers with Java 6 support contracts. For some unknown reason the company did not see this would cause a problem for JDK 7 users being unable to keep their time zone data up to date.

Time zones are adjusted regularly around the world by local authorities and keeping synchronised can be a near constant task. The tz database, which used to be called the Olson database, acts as a reference for all this information. After a copyright claim in 2011, later dismissed, the database moved to the Internet Assigned Numbers Authority (IANA), where it is regularly updated.

The tzupdater tool is built using that database, converted it into the format required by Java, and patches Java installations with the updated information. Oracle update Java to the latest time zone data in JDK and JRE releases whenever they release a maintenance or update version, but there are users who need to ensure they always have to most up to date version of the time zone database installed; for them, Java maintenance updates do not happen quickly enough. Although details of how to build your own time zone updating tool were available, the removal of the tzupdater tool was seen as Oracle forcing users to sign up for a support contract. The removal was brought up in various forums last week.

In the announcement of the reversal, Oracle's Henrik Stahl explained that the inability to update JDK 7's time zone data was "not in line with our policy" and that "The most recent version of the Oracle JDK will always be available royalty free (including any tools required to keep it up to date)". Oracle is, says Stahl, also looking for ways to reduce the gap between time zone database updates and JDK/JRE updates. The tzupdater tool is available to download as is documentation on its use.

(djwm)