This is the latest version:

20261111-vivaldi-datumsformat-0.png

The picture #1 shows the setting the date setting "like UI", but it shows the US-version instead. Picture #2 shows the desired version date and time of xfce4. Selecting the preferred date & time forat "like OS" does not change anything.

20261111-vivaldi-datumsformat-1.png

20261111-vivaldi-datumsformat-2.png

How can I get german date and time in Vivaldi browser?