Is a school scheduling configuration in which students K-12 students in the United States attend school year-round, with intermittent breaks scheduled throughout the year. Year-round schools are usually set up as single-track (ST) with unified attendance or multi-track (MT) with staggered attendance programs. Some schools use a combination of the two. The main difference between the two systems is that single-track allows the entire student and staff population to adhere to the same calendar, and multi-track separates students and teachers and places each in one of several staggered instructional blocks and vacation schedules.

To make this even more complicated, the single-track and multi-track systems can have different variations. In the 60-20 schedule, the school year is separated into three sixty-day sessions with three twenty-day vacations. A variation on this schedule is the 60-15, which provides for an additional three- to four-week collective vacation. This plan can be used with either the single-track or multi-track system. Collectively, these calendars are used by a little more than a third of year-round schools in America.

Lastly, let’s talk about two year-round calendars that are used by around 40 percent of year-round schools. In the 45-15 schedule, forty-five days of instruction are followed by fifteen days of vacation time. The related 45-10 schedule provides an additional four-week vacation for staff and students. Again, these plans can be implemented in either a single-track or multi-track system.