20 January 2023, EU Commission published a list of high-value datasets that public sector bodies will have to make available for re-use, free of charge, within 16 months. So that would be May 2024
The focus is on data with important benefits for society, the environment and the economy – which is why they should be made available to the public
The Regulation is set up under the Open Data Directive, which defines six categories of such high-value datasets: geospatial, earth observation and environment, meteorological, statistics, companies and mobility. This thematic range can be extended at a later stage to reflect technological and market developments.
The datasets will be available in machine-readable format, via an Application Programming Interface and, where relevant, as bulk download.
List is here
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2023.019.01.0043.01.ENG
Public sector bodies shall designate a point of contact for questions and issues related to the API with a view to ensure the availability and maintenance of the API and ultimately the smooth and effective publication of the high-value datasets.
By 2 years after entry into force of this Implementing Regulation Member States shall provide the Commission with a report on the measures they have carried out to implement this Implementing Regulation.