Will Woods pointed out on #fedora-meeting that he adds a second clock to the gnome panel to track UTC for Fedora meeting times. I’ve been looking for a good multiple timezone clock for a long time. It is possible to add a second clock and set it to display UTC.

Add a second clock applet to the Gnome panel, right-click on it, select preferences, and check UTC.

There doesn’t appear to be a way to label the new clock as UTC.