Since the update to 18.04 from 16.04, i see top bar with date and time only on the primary screen of my notebook. On the other screens the top bar is not shown.
Another anoying thing is i see only the actual weekday and time of the day. I would like to see the whole date with time without clicking on it...
I've searched along by google but i didnt found a solution...
Install GNOME Tweak Tool:
Go to Top Bar on the left and enable date under clock.
You can change setting from terminal too using following command.
$ gsettings set org.gnome.desktop.interface clock-show-date true
Installing "Multi Monitors Add-On" showed topbar on both my displays.
Software Center, search "Multi Monitors Add-On", Install.
Its option "Show Panel on additional monitors" is turned on by default.