I noticed the Groovy 2.5.0 documentation reflects the extension methods added to the java.time package and sub-packages ( http://groovy-lang.org/groovy-dev-kit.html#_working_with_date_time_types), but the Groovy JDK docs do not mention them (http://groovy-lang.org/gdk.html ).
The necessary files are included in docs.gradle, however ( https://github.com/apache/groovy/blob/GROOVY_2_5_X/gradle/docs.gradle#L157-L159), so perhaps this a publishing issue? -Joe
