When I click the current time from the top right corner it will expand a calendar view. How can I add week numbers to that calendar? Time & Date settings have basically no options at all.
Hi, and welcome back to the community ! 
You can set this with:
-
A GUI, using
dconf-editor
Assuming you're using Ubuntu MATE 20.10
, it's located in
org.ayatana.indicator.datetime. Just setshow-week-numberstotrueinstead of thedefault valuethat isfalse.
Should you be using Ubuntu MATE 20.04 LTS
, it would be located in
com.canonical.indicator.datetime. -
A terminal
with
gsettings set org.ayatana.indicator.datetime show-week-numbers trueif you're using Ubuntu MATE 20.10
or
gsettings set com.canonical.indicator.datetime show-week-numbers trueif you're using Ubuntu MATE 20.04 LTS
.