Show *year* on Ubuntu 20.04 top bar

As far as I can tell, there are no tweaks for showing the year on the top bar clock in Ubuntu 20.04 (Focal Fossa). I find it for < 20.04, but I can't find a suitable solution for Ubuntu 20.04.

Our service frequently needs to take screenshots identifying the year of a screenshot and the Ubuntu clock only believes in hour minute seconds date and day of week. That doesn't help people who need to record the year in a screenshot.

I needed the same thing, and nerd-sniped my friend Stuart Langridge to develop this functionality. He made a great GNOME Extension called Clock Override which enables you to put whatever you want in the clock area in the centre of the screen.

You can configure it to say anything. The settings below will show a very verbose time such as "2021-03-06T23:23:00+00:00" but you can of course make it say something shorter.