The only two we have in common are Wikipedia and The Time.
To make sure we are talking about the same time app you can check the details in the app store program - mine was developed by Jeff Key (it's a green tile).
Outside of metro apps I installed Stardock's Start8 button but I stopped that program for an hour or so and it did not seem to make any difference to the behaviour of Runtime Broker so I am ruling that out as a potential troublemaker for now.
I'm going to uninstall the two apps we have in common (one at a time) and see if it has any effect at all but I am not overly optimistic.