Hi Susan!
Thanks for your question and for visiting the Disney Parks Moms Panel!
You ask an interesting question as thousands of Guests from around the world check in each day to the
resorts of
Walt Disney World.
Although I am sure there are members of management somewhere who keep track of these types of statistics, they are generally kept pretty well under wraps. That said, I will go out on a limb and say that the busiest check-in days, in my experience, are exactly what you think they would be...Saturdays and Sundays.
I have checked in on virtually every day of the week, and it seems that most often, Guests like to vacation from either Saturday to Saturday or Saturday to Sunday.
Obviously there is some variation to what I am saying, but in the absence of hard data, I am giving you my best information based on personal experience.
Checking in midweek has made me feel like my girls and I are the only ones on a given property sometimes.
I hope this helps and I wish you a Magical trip!!
Chris