Extended Date Time Format for Wikibase

We are happy to announce the release of Wikibase EDTF, our latest Wikibase extension. As the name suggests, Wikibase EDTF adds support for the EDTF standard to Wikibase.

EDTF stands for Extended Date Time Format. The EDTF standard adds new date formats to ISO 8601-2019 2, including support for intervals, sets, uncertainty, precision, and seasons. It was published by the US Library of Congress in 2019, after joint creation of the standard with the wider bibliographic community.

The new Wikibase EDTF extension adds an EDTF datatype to Wikibase, which supports the full EDTF specification. In other words, you can now have a property with type “Extended Date Time Format”, and then have statements with values like “15XX-12-25” or “{2010,2015..2020}”. This allows you to express dates that are too complex for the native Wikibase date format (ISO 8601-2004).

Wikibase validates the input, ensuring only valid EDTF values are stored. Furthermore, the user interface shows a “humanized” version of the EDTF value, which makes the value easier to understand for those unfamiliar with EDTF.

We created Wikibase EDTF for the Luxembourg Ministry of Culture, who financed the work. Professional Wiki thanks the Ministry for funding the project. Special thanks also go to Maarten Zeinstra, Maarten Brinkerink, Lucien Wagener, Claude Dessouroux, and Chaudry Abubakr for their contributions.

Wikibase EDTF is available as free open source software (GPL V2) that can be installed on any Wikibase 1.35 instance. It relies on a new PHP EDTF library we developed for the project, which is also open source. We welcome contributions to both the Wikibase EDTF extension and the EDTF library!

You can commission the Wikibase Consultancy for Wikibase software development. Our other Wikibase services include managed Wikibase hosting and Wikibase setup. Contact us for more information.