My last three years, Sundays have been awful.  I am usually there the third, fourth, or fifth week of the event and still, Sundays have been my absolute least favorite days.  I actually have had better luck on Saturdays than Sundays the last two years.  I am curious as to other's thoughts, but figured I would just weigh in with my recent experiences.  All that being said, we are purposefully not going on a Sunday this year as all five of my group have loathed our experiences on that particular night.