Nowadays, children spend a lot of time sitting still in the classroom. This can be an especially big disservice to children with Autism and Asperger's.
I find this original classroom schedule put together by Maria Montessori to be a fascinating contrast with classroom programs today!
Opening at Nine O'clock–Closing at Four O'clock
9-10. Entrance. Greeting. Inspection as to personal cleanliness. Exercises of practical life; helping one another to take off and put on the aprons. Going over the room to see that everything is dusted and in order. Language. Conversation period Children give an account of the events of the day before. Religious exercises. Note that religion and life in Italy during this time were closely intertwined
10-11. Intellectual exercises. Objective lessons interrupted by short rest periods. Nomenclature, Sense exercises.
11-11:30. Simple gymnastics: Ordinary movements done gracefully, normal position of the body, walking, marching in line, salutations, movements for attention, placing of objects gracefully.
11:30-12. Luncheon: Short prayer.
12-1. Free games.
1-2. Directed games, if possible, in the open air. During this period the older children in turn go through with the exercises of practical life, cleaning the room, dusting, putting the material in order. General inspection for cleanliness: Conversation.
2-3. Manual work. Clay modelling, design, etc.
3-4. Collective gymnastics and songs, if possible in the open air. Exercises to develop forethought: Visiting, and caring for, the plants and animals.
As soon as a school is established, the question of schedule arises. This must be considered from two points of view; the length of the school-day and the distribution of study and of the activities of life
Definitely not a day full of sitting indoors quietly!