The Time Zone database release was only announced 17 hours ago (on 2016-01-28).
There will be a new version of the tzinfo-data gem for every release of the Time Zone database.
New versions of the old tzinfo 0.3 branch will be released occasionally if there are significant data changes. However, I'm planning to drop support for 0.3 once there are no longer any supported Ruby on Rails versions that rely on it (i.e. once support for Rails 3.2 is withdrawn).