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Making time: Q&A

How is time typically organized in schools (e.g., length of day, school year)?

The public school day and year has not changed much over the past 100 years, with most students attending between 6 and 6.5 hours for 180 days. The average public school day was 6.3 hours in 1988, but rose slightly to 6.5 hours in 2000. These hours vary slightly across public school levels. At 6.8 hours, middle school students have the longest average school day. High school students average 6.6 hours, and elementary school students average 6.5 hours.

The length of the school year is typically calculated in the number of minimum days or number of minimum hours. Most states (in 2004, 34 states  and the District of Columbia) now require a minimum of 180 school days. There is some indication that states are lengthening their school year—five states now require more than 180 instructional days, compared with four in 2000, and just one in 1994. Only four states now require fewer than 175 days. In 2004, 40 states and the District of Columbia set regulations for public school instruction on minimum hours per day. Thirty-four of those states required five or more instructional hours per day in grades one through high school.


Are schools moving away from the traditional September–June calendar?

Not really, although the traditional start date has crept into August. In 1988, just over half the nation’s schools opened before September first; in 2000, three-quarters did—this represents a 50 percent increase. This pattern often occurs in the South and the Midwest, where some schools begin in late August but have a one- or two-week break at fall harvest time. Only a few states have laws requiring schools to start on a certain date, most often leaving it to the discretion of local education agencies. Several of the states that do have mandatory start dates appear to have implemented such policies to address the concerns of the state’s tourism industry rather than address education needs. (Michigan, Minnesota, and Virginia all require their schools to start after Labor Day.)

A small portion (7 percent) of all public schools use a “year-round” or “modified” calendar in which instruction is distributed throughout the calendar year. This type of calendar is a bit more prevalent among charter schools, with 12 percent operating on a year-round schedule.


Are year-round schools effective?

Districts and schools that have turned to year-round schedules or a modified calendar typically do so for one of two reasons: To combat summer learning loss or to address overcrowding. It is estimated that more than half of year-round schools adopt a calendar that maximizes student learning and addresses summer learning loss.

Although much of the research on year-round schools is based on small samples, a few research summaries indicate a positive relationship between this schedule and academic achievement, particularly in the subjects of reading and math. This research concludes that students attending year-round schools “are likely to perform as well as, if not better than, their peers in traditional nine-month programs.”  But the research body has several limitations. Almost three-quarters of the studies focused on the elementary level. Few specified the type of year-round calendar or whether it allowed for additional days of instruction through intersessions or other extended learning programs. The small handful of studies that attempted to examine the effects of intersessions suffered from poor research design.


Are there special scheduling considerations for students at different levels (i.e., kindergarten, elementary, high school)?

Despite recent research showing that children attending full-day kindergarten perform better in math and reading, half-day kindergarten is still the norm. Although most states (41 and the District of Columbia) require that public schools offer a kindergarten program, only nine states require full-day programs (compared with 10 in 1995). In comparison, 23 states require half-day kindergarten programs, 12 states require either of the two, and only nine states report no policy on the matter.

School officials recognize the need for more instructional time as students develop, which is evidenced by variations in scheduling across school levels. At 6.8 hours, public middle school students have the highest average school day, followed by high school students at 6.6 hours, and elementary school students with 6.5. Though national data on school start times is not available, some reports indicate that high schools are pushing back their start times in response to recent research suggesting that the sleep-wake cycle shifts during adolescence lead to teenagers’ natural tendency to fall asleep later and wake up later. Another recent study from Northwestern University found that high school students perform best later in the day than early in the morning; therefore, most high school schedules contribute to students’ sleep deprivation. Both Tulsa, Oklahoma, and Minneapolis, Minnesota, serve as examples of school districts that have pushed back their high school start times to later than 8:00 a.m.


What are the advantages and disadvantages of a block schedule?

One-third of all public schools now use block schedules—schedules that offer classes in longer blocks of time (usually 90 minutes or more) with subjects offered on alternating days or alternating semesters or trimesters. There are several structures for these schedules, though two are most common, the 4X4 Block and the Alternating Plan.

  • 4x4 Block: The school day is divided into four blocks, with each block lasting anywhere between 85–100 minutes. Time for lunch and transitions are separate. Students complete in one semester what would have taken a full year in traditional schedules.
  • Alternating plan (also known as the Eight-Block plan or the A/B Plan): Students attend eight blocks of classes (again, typically 90 minutes long) over two days.

Advantages of the 4X4 Block (and of similar schedules known as the trimester plan and the 75-75-30 plan) include:

  • Students and teachers receiving increased instructional time.
  • Teachers and students preparing for fewer courses each trimester or term.
  • Teachers working with fewer students during a trimester.

The main disadvantage is that students may not retain knowledge from fall courses when taking state and other standardized tests in the spring.

In comparison, the Alternating Plan’s advantages include:

  • Students and teachers increased instructional time.
  • Fewer classes, quizzes, and homework assignments for students each day.

The Alternating Plan’s disadvantage is that teachers still have a large number of students. They are just spread over two days.

Research on block schedules has shown mixed results on academic achievement, although results depend on the type of schedule used. Based on a few studies comparing results between block and non-block schools on college admissions or AP scores, the 4X4 Block Schedule seems to produce the least gains. One of the studies did find a slight increase in mean ACT scores for students on an Eight-Block (or A/B block) Schedule.


What are effective models for organizing time in school to maximize time for instruction?

Proponents of block scheduling suggest that teachers are able to focus instruction and delve more deeply into materials, because less time is spent on transitions between classes and classroom management activities, such as calling attendance and organizing and focusing the class. In addition, studies indicate that discipline issues decrease with block schedules.


What effective time-organization models help schools provide extra support for struggling students?

Intersessions (one or two-week sessions held during breaks) in year-round schools and block schedules are seen as two methods for supporting struggling students. Although there is little empirical data that supports using intersessions for improving academic achievement of at-risk students, most year-round programs target students through such initiatives based on their understanding of summer learning loss research.


What are effective models that organize time in school to support teachers’ professional development?

Block schedules provide longer periods for teachers to participate in professional development and curriculum-planning sessions. Four-day school weeks free an entire day for teachers to participate in professional development or team planning (depending on contract stipulations). (Only a few studies examined the impact of year-round schooling on professional development, and these results were mixed.)


Are there examples of schools or districts that use time effectively?

Students at Roxbury Preparatory Charter School in Massachusetts attend classes for eight hours each day and receive double the instructional time for math and language arts. As a result, the percentage of students passing the MCAS (the state’s standardized test) increased dramatically.  In 2002, only 70 percent of the students passed the eighth grade math MCAS (they did not have double math classes until their eighth grade year). In 2004, one hundred percent of the students passed the MCAS (they had three years of double math).

New York’s Central Park East Secondary School organizes 7th- through 10th-grade teachers into interdisciplinary core courses (math/science or humanities). Two groups of students meet daily for two hours each. (In 11th and 12th grade, teachers offer more specialized courses and advisement for the ambitious portfolio assessments students must complete to graduate.) These teachers average seven-and-a-half hours each week for joint planning, in addition to five hours of weekly personal planning time. The bulk of this time comes from a weekly full-morning meeting with teams in their discipline (while students are engaged in community service placements). Other reforms may also impact the school’s success—Central Park East has also reduced class sizes and implemented “houses” or “small learning communities.” Nevertheless, the school’s annual graduation rate is more than 90 percent, and more than 90 percent of those graduates go on to college.

A small rural school in Kentucky’s Webster County adopted a four-day school week in 2003–2004, after an intensive planning process found that most absences for students and staff occurred on Mondays and Fridays, and most holidays were on Mondays. District officials reviewed other districts with four-day school weeks and ultimately adopted a Tuesday–Friday schedule. Because Kentucky defines the school calendar in hours instead of days, the district was free to organize its time into 163 student instructional days instead of the traditional 175-day model (students attend school for 1,050 instructional hours per year, and attend a minimum of six instructional hours every day). In just two years, the district documented increased scores on all areas of its Comprehensive Test of Basic Skills, decreased suspensions and code-of-conduct violations, and increased collaboration and planning among teachers. This, in turn, improved academic rigor and lesson preparation along with the ability to cover more core content during the school year.


What should school boards consider before modifying the school period, day, or year?

The Northeast Lab suggests the following actions:

Consult external resources: Visit schools and other communities that are actively involved in the scheduling change under consideration to observe classes and speak directly with those affected by the new schedule.

Involve teachers, administrators, students, and parents: Ownership of a new schedule or strategy cannot occur without the input of all stakeholders. Success with a new schedule depends on the involvement of all participants in the transformation and a sense that each constituency has its voice heard. Surveys, interviews, focus groups, and informal discussions can help.

Provide professional development: As with any new program, the needs of teachers should be determined and addressed throughout the year. This is especially important for block scheduling, since teachers may need to learn new strategies for presenting information in a number of different formats.

Seek constant feedback: Use formal and informal methods to evaluate the schedule change. For example, collect feedback from teachers, students, and parents through community-wide or school-wide forums, surveys, or focus groups.

Collect and maintain data on teacher and student performance: Use data to monitor what is and is not working. Share that information with teachers and staff.

Make a long-term commitment to your schedule change: Recognize that a new strategy or schedule requires sufficient trial time and develop a multi-year implementation plan.

Ensure that schedule changes are incorporated into broader goals for your district and school: It is important to ask yourself the following questions:

  • How does it fit in our overall plan for school improvement?
  • How does it integrate with other teaching and learning strategies?
  • Has our school laid the groundwork for its successful implementation?
  • Is there a plan for measuring progress?




This document was prepared for the Center for Public Education by Eileen M. O'Brien, an independent education researcher and consultant in Alexandria, Virginia. Much of O'Brien's work has focused on access to quality education for disadvantaged and minority populations. She has a master of public administration from George Washington University and a bachelor of science degree in psychology from Loyola University of Chicago.

Posted: September 21, 2006

©2006 Center for Public Education

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