Brian Tillman wrote:

To the best of my knowledge, you cannot eliminate the Date Navigator
from the Navigation Pane except by using the To Do bar. However, you
could display the To Do bar, and then collapse it. It wouldn't be
very intrusive in that case.

It turns out that minimizing the To Do list will put the Date Navigator back
above the folder list. If you drag the To Do's left edge toward the right,
however, you can make it much smaller. As long at you don't reduce its size
to the minimum, the Date Navigator will remain mostly obscured on the right
side.
--
Brian Tillman [MVP-Outlook]