It varies by season. A lot has to do with which Park has early morning or later evening hours for resort guests.
Honestly it's always busy
I recently spent 2 days, morning to night, it was busy day, lot of people.
We went in October last year and every day, every park, was full to capacity, one day we as a family where actually concerned from a safety perspective as it was so busy, especially leaving The Magic Kingdom Park after the night fireworks. Without fast passes, expect 90min + waits for any ride, and up to 3hrs for The Avatar ride.
There are no busy days in Disney.
Always is busy y this weekend is too busy
Thanks! Your answer is awaiting moderation.