Most of these people attend maybe a teleconf call every month or two, plus the time they spend working on the "strategic direction" for the company. Directors' 1st responsibility is actually to make sure whatever the company is doing is for the best interest of all shareholders, then it comes down to reviewing business general developments.
My experience is that they are there to provide some kinda of strategic safety net for the people who is running the business, to assist as a think tank and provide vital business connections for the most useful part, introducing the team to potential business partners.
It's not necessary and realistic to ask for these non-exc chairman & directors to work full time or exclusively, business operation and decisions are still being made by owners, they are mostly there only to shadow over Pivacs' shoulders and say "looks good, continue!".
