1## Update tzdb 2 3ThreeTen-Backport contains a set of time-zone information independent of the JDK. 4This can be updated when time-zone rules change. 5There are two ways to update the data. 6 7 8## Build separate tzdb.jar 9 10The first option is to build a standalone tzdb file. 11The generated jar file is added to the classpath in addition to the standard threetenbp.jar file. 12 131. Clone the [source repository](https://github.com/ThreeTen/threetenbp) from GitHub 142. [Download](https://github.com/JodaOrg/global-tz/releases) the latest rearguard time zone data 153. Extract and copy the rearguard files from `tzdata{tzdb-version}-rearguard.dir` to the folder `src/tzdb/{tzdb-version}` inside the threetenbp source 164. Run the maven command `mvn clean package -Dtzdb-jar` 175. Add the resulting tzdb-{version}.jar file in the `target` folder to your classpath 18(ignore the tadb-all.jar file) 19 20This is the preferred approach as it separates the tzdb data from released code. 21 22 23## Rebuild threetenbp.jar 24 25The second option is to rebuild the main threetenbp.jar file. 26The generated jar file will replace the standard threetenbp.jar file. 27 281. Clone the [source repository](https://github.com/ThreeTen/threetenbp) from GitHub 292. [Download](https://github.com/JodaOrg/global-tz/releases) the latest rearguard time zone data 303. Extract and copy the rearguard files from `tzdata{tzdb-version}-rearguard.dir` to the folder `src/tzdb/{tzdb-version}` inside the threetenbp source 314. Change the version number in the maven pom to indicate it is your unoffical build 325. Run the maven command `mvn clean compile` 336. Run the maven command `mvn package -Dtzdb-update` 347. Use the resulting threetenbp.jar file in the `target` folder 35