Install prerequisites:
sudo apt-get install -y gir1.2-timezonemap-1.0 gir1.2-gweather-3.0 gnome-clocks
Go to https://extensions.gnome.org/extension/697/panel-world-clock/ and click the button
Install prerequisites:
sudo apt-get install -y gir1.2-timezonemap-1.0 gir1.2-gweather-3.0 gnome-clocks
Go to https://extensions.gnome.org/extension/697/panel-world-clock/ and click the button