showing the date on the gnome3 "top bar"

[Allan Gottlieb <gottlieb nyu edu>]

I have gnome3 running on two machines and am quite happy with it.

Somehow on one machine, when I am logged in, the center of the top bar
has the time with the day of the week, e.g.,

                  Tue 11:56 PM

The other includes the date as well, something like

                 Tue jan 24, 11:56 PM

I prefer the latter but can not find the button to press to change the
format.  I have clicked all over "date and time settings".

thanks in advance,
allan