Yes, absolutely. Scheduled conference calls were a part of my life long before most people had home or office Internet. At work, for discussions with regionally-based librarians and other co-workers, we'd usually schedule them for early afternoon, say 1 or 1:30PM. That way, we didn't usually bleed too far into lunchtime for people in Vancouver, or too close to their going-home time in the Atlantic provinces. Family and social-group conference calls can work too, especially when the group is far-ranging geographically (though it's useful if they are at least in the same hemisphere!)