Since I work with software professionally, I have learned two things. The first one, that dates that are not in the “YYYY-MM-DD” format (see ISO 8601[https://en.wikipedia.org/wiki/ISO_8601] for more details) are harder to understand, and the second one, that Germans love to use Calendar Weeks to talk about deadlines (also defined in the previous standard), which turns out really useful.
To my surprise, or my ineptitude, I was unable to display both the CW and the YYYY-MM-DD date in my gnome3 desktop. So, I took matters into my own hands and decided to check out how to do this.
This was one of the times when using Claude for research turned out to be great. Since Gnome is an Open Source project, it was pretty easy to point Claude towards the problem and ask it to solve it.
Gnome3 uses the GTK framework for the UI Toolkit.