Might be related to today's yearly 'Prinsjesdag' in the Netherlands:

The day on which the reigning monarch of the Netherlands addresses a joint session of the States-General of the Netherlands (consisting of the Senate and the House of Representatives) to give the Speech from the Throne (Dutch: Troonrede), similar to the annual State of the Union in the United States or the British State Opening of Parliament. This speech sets out the main features of government policy for the coming parliamentary session.

https://en.wikipedia.org/wiki/Prinsjesdag