I sometimes forget what day it is, so I changed my planner template to
something that fills in the day, too.

(defun sacha/planner-day-page-template ()
  "Day page template for Sacha."
  (let ((date (planner-filename-to-calendar-date (planner-page-name))))
    (insert "Headlines for "
            (calendar-day-name date)
            ":\n\n\n\n* Tasks\n\n\n* Notes\n\n")))
(setq planner-day-page-template 'sacha/planner-day-page-template)