Time zone information

JRuby relies on joda-time to handle time zone data structures. joda-time, in turn, relies on the so-called Olson database for the time zone information.

In the current master branch (as of January 6, 2011), it is possible to update the time zone information to the most up-to-date version of the database.

To do this, use the ant target update-tzdata.

With the help of Apache Commons Net library, it will fetch and expand the most up-to-date (well, the version indicated as such in default.build.properties) archive from the archive, compiles the source and rebuilds the joda-time jar. Subsequent invocation of the jar (jar-complete) will use this new jar file.

  ant clean update-tzdata jar

You can find out which version of tzdata archive is compiled for JRuby as follows:

  require 'rbconfig'
  RbConfig::CONFIG["tzdata.version"] # => "2010k"