JDemetra+ is a new open source tool for seasonal adjustment (SA) that enables the implementation of a revised ESS Guidelines on SA. It has been developed to provide a set of reusable and extensible components, following a standard technology, compatible with the environment of most European statistical institutions. JDemetra+ is not only a user-friendly graphical interface, comparable to its predecessor, Demetra+, but also a set of open Java libraries that can be used to deal with time series related issues like the SA processing of large-scale data sets, non-standard SA methods, the development of advanced research modules, temporal disaggregation, benchmarking and business cycle analysis.

JDemetra+ is built around the concepts and the algorithms used in the two leading SA methods, i.e. TRAMO/SEATS and X12-Arima/X13-Arima-Seats. They have been reengineered, following an object-oriented approach, that allows for easier handling, extensions or modifications.

The software has been developed by the National Bank of Belgium in cooperation with Eurostat.