For as long as I can remember, my productivity has been guided by two things: my task list and my calendar. However, these two items have rarely truly been managed in tandem.
I would set appointments with clients, for meetings or personal activities and then the time I had left was available for my task list. For some of my job positions (particularly some of my first jobs) this actually made sense. But as I moved up in management it probably was not so wise. And now as a solopreneur, it is even less so.