How do I update my calendar?

How do I mark it fully booked for the day? I have a confirmed booking for this weekend (Fri - Sun) and then a pending booking for Sunday to Monday....my calendar shows Friday and Saturday as fully booked but Sunday and Monday as free....I don't get it. If I click on the day I can only change the number of dogs willing to take in but not the number of booked dogs. What am I missing?