How do I customize the date/time display in GNOME Shell's top bar?

Question

Time indicator is shown as "%a %H:%M" in the center of the top bar.

How do I move it back to the right where it belongs, and make it include the full date and time ("%Y-%m-%d %s %H:%M")?

Answer 1

You may achieve your goal using some GNOME shell extensions.

Moving clock to the right

You may use Frippery Move Clock.

See this Q&A for more options.

Changing date & time format

You may use Clock override. It lets you

Override the Gnome Shell clock with a new time format or text of your choice.

It supports Python's strftime format (so you'll be able to set your preferred "%Y-%m-%d %s %H:%M" format to display).

Answer 2

Panel Date Format is another GNOME Shell extension that allows you to modify the formatting of date and time in the top panel, e.g. to include the current week number.

I used

dconf write /org/gnome/shell/extensions/panel-date-format/format "'%a (KW %V) %d.%m.%y %H:%M'"

to display below format:

Answer 3

Another place to look:- Ubuntu Software Centre - certainly in Ubuntu 17.10. If you search for "clock" a whole list of different programs is displayed, Clock Override among them.