I work at the Urban School of San Francisco, an independent progressive high school. Our schedule is a refinement of a schedule I designed a number of years ago. It is based on a four-period day, and three 12-week quarters.
At any time, a student is taking four classes. Because of the long periods, a one-year course takes 24 weeks to complete (two quarters). A one-semester course takes one quarter (12 weeks.)
The school day goes from 8:30 to 3:00.
A given course meets three times a week for 70 minutes, and once a week for two and a quarter hours (not continuous: there's a 15 minute break). The "long day" class takes all morning, or all afternoon.
The four periods are called A, B, C, D. The week looks like this:
Mo: A, B, C, D Tu: A, B, C, D We: A, C Th: B, D Fr: A, B, C, D
In addition we have
* a weekly 30-minute meeting of teachers with their advisees, (a sort of homeroom.)
* a weekly 30-40 minute all-school assembly
* two weekly "consultation and study periods" (office half-hours -- students can request or be required to meet with any teacher)
Advantages of our schedule:
* the three 70 minute periods give enough time to do something in depth, or preferably to do more than one activity -- eg group work, all-class discussion, labs with manipulatives or graphing calculators, etc. (Of course, each department interprets it their own way.)
* the half-day period makes it possible to take field trips, pursue major projects, do ambitious labs, see movies, etc. It is even possible to extend into lunch, making for an even longer stretch.
* students are juggling fewer subjects and can concentrate better on those they are taking -- both at home and in class. The atmosphere is less frenetic.
* teachers see fewer students a day, and know them better
* teachers usually teach three periods, consisting of two different preps
* there are far fewer homework opportunities (less than 96 assignments, instead of the normal less than 180) -- however assignments can be more substantial.
* at some times, when students are taking "four solids", it's a lot of intensity. However a typical quarter involves three academic classes and one art class, or an off-campus project, or other non-academic class.
* planning longer periods can be challenging for teachers who are new to this -- but it's also rewarding when you get the hang of it
We have been doing this for many years, and it works well. For more info, email me.