Common Forms of Block Scheduling

The two most common block scheduling formats are the alternate-day schedule, also called the “A day, B day” schedule or the “Day 1, Day 2” schedule, and the 4x4 semester schedule.

Alternate-day schedules meet classes in blocks every other day for the entire school year and come in several varieties. In the six-course format of the alternate-day schedule, six classes meet every other day in three blocks of 100-120 minutes. Because teachers generally instruct five of the six classes, they have a planning block every other day.

In the seven-course version of this schedule, six classes meet in alternate-day blocks that are between 80 and 95 minutes in length and one class meets daily as a single 45- to 50-minute period. The single period typically falls in the 5th period slot with lunch periods built around it, although occasionally it is placed in the 1st, 3rd or 7th period. Teachers instruct either five or six of these courses.

In the 8 A/B schedule, eight classes meet every other day in four blocks of 80-95 minutes.

The other common model is the 4x4 schedule (known as “four-by-four”) in which classes meet every day in 80- to 95-minute blocks for one semester. Because certain classes such as band, orchestra, choir and ROTC must meet throughout the entire year, ideally this schedule is modified by embedding an A/B schedule, or “skinnies,” into one or more blocks. We prefer embedding an A/B schedule over skinnies to keep all classes in block format and to avoid any mid-block class changes.