My planners have evolved over the years as my life as evolved. I was part of the filofax/day runner crew in the late 70's, early 80's to track my work life. Then when I moved from headquarters to reservations and was doing shift trades of all kinds, a calendar was necessary just to keep track of trades.
Then with kids and their activities and school schedule, including them on my calendar became a necessity. So I have a month-at-a-glance, week-at-a-glance where I put my to-do's for the week, then journaling space. At the back I have tabs for keeping Ideas, Presents, and Projects and an Index.