I find that the Java 8 java.time API [1] easier to understand than Joda Time [2] when working with timezones. In particular, the OffsetDateTime and ZonedDateTime classes in java.time seem well-designed and easy to use. The equivalents in Joda Time are harder for me.
[1] https://docs.oracle.com/javase/8/docs/api/java/time/package-...
[2] https://www.joda.org/joda-time/apidocs/index.html