Key Lessons: What Research Says About Reorganizing School Schedules

Like class size reduction, increasing instructional time has lots of common-sense appeal as mechanism for raising student achievement. But more time in school can be costly. These key lessons summarize the current research on different approaches to organizing school time and schedules, beginning with the obvious question: Does more time make a difference?

Like class size reduction, increasing instructional time has lots of common-sense appeal as a mechanism for raising student achievement. It just stands to reason that more time for learning equals more being learned. But like smaller classes, more time in school can be costly, especially if it's gained through lengthening the school year or adding time to the school day.

Several pioneering districts and schools have tried different strategies for making more time available for instruction by reconfiguring schedules to use available time and resources more effectively. The following key lessons summarize the current research on different approaches to organizing school time and schedules, beginning with the obvious question: Does more time make a difference?

  • More school time produces more learning when the time is focused on academic activities.

    While most researchers find a generally positive relationship, one meta-analysis suggests that extra time does not in itself make a difference; rather it's how the extra time is used. For schools, this means "maximizing the time during which students are actively and appropriately engaged in learning," or what is often simply called "time on task" (Walberg, 1998; Aronson, Zimmerman, and Carlos, 2005).

  • Professional development is key.

    Teachers trained in traditional modes of instruction, including the reliance on lecture, will likely need appropriate professional development to make the best use of class time and keep students actively engaged (Irmsher, 1996; Farbman and Kaplan, 2005).

  • Students in full-day kindergarten post more gains than their peers in half-day programs.

    Younger students seem to benefit from more school time regardless of other factors. While half-day kindergarten is still the norm, researchers have found that children in full-day programs learn more during the year in reading and math (Walston and West, 2004).

Using existing time differently

Across the country, the traditional school calendar — nine months of six hour days, September through early June — prevails as it has for over a century. However, many districts and schools are attempting to use this time more efficiently by implementing different strategies: Year-round schools, block schedules, and four-day school weeks.

  • Year-round schools have a positive relationship to academic learning, especially in reading and math.

    Rather than adhere to a nine-month calendar, year-round schools spread their allotted 175-180 days over 12 months. Districts and schools typically turn to year-round schedules for one of two reasons: To avoid the learning loss that often occurs over the long summer break, or to alleviate over-crowding by organizing multiple tracks for student attendance. Few studies examined single-track versus multi-track, or specific types of year-round schedules. Overall, however, research indicates a positive impact on students (Palmer and Bennis, 1998; Cooper, Nye, Charlton, Lindsay, and Greathouse, 1996; Kneese, 1996).

  • Block scheduling is intended to increase "time on task," but the achievement results are mixed with the so-called 4X4 block producing the least gains.

    Block schedules reorganize the traditional 45-minute class period into longer blocks of time that are usually 90 minutes or longer. There are various ways to configure blocks. Some schedules, including the 4X4, concentrate a traditional year-round course into a single trimester or semester. Students in this type of block schedule score the lowest on exams compared to their peers in traditional programs or other block configurations (Harmston, Pliska, Ziomek, and Hackmann, 2003; The College Board, 1998).

  • Four-day school weeks were designed to help save overhead costs, but also appear to have educational and morale benefits for students and staff.

    Many rural districts have dropped one day from the weekly schedule by adding time to the other four days. While the move is almost always initiated to save on transportation and food service expenses, some are seeing unintended benefits in the form of higher test scores, decreased disciplinary problems, greater collaboration among teachers, and higher morale (Dam, 2004; Yarbrough and Gilman, 2006).

Finding more time for teachers and students

Even if block and other non-traditional schedules don't lead to higher achievement gains, there could be other worthwhile benefits.

  • Reconfigured schedules can provide a weekly block of time for staff planning, professional development or collaboration.

    Different models for reorganizing the schedule can carve out from two- to-seven hours for teachers and staff planning each week.

  • Block schedules can be used to extend extra time to struggling students.

    Some schools have produced significant gains by adjusting the schedule to provide double periods in math and language arts for students who need it. Longer classes can also make it easier for teachers to differentiate the instruction according to students' needs (Farbman and Kaplan, 2005).

  • Starting high school later in the day leads to better attendance and more alert students.

    Researchers have found that starting the school day early works counter to the natural sleep cycles of teenagers. High schools that moved their start times back report better student attendance, less sleeping in class, and even fewer instances of student-reported depression (Graham, 2000; Tonn, 2006; Wahlstrom, 2002).


Click the "References" link above to hide these references.

Aronson, J., Zimmerman, J., and Carlos, L. (2005). Improving student achievement by extending school: Is it just a matter of time? Retrieved on June 19, 2006, from WestEd:

The College Board. (1998, May). Block schedules and student performance on AP examinations. Research Notes, RN-03. New York: Office of Research and Development, The College Board.

Cooper, H., Nye, B., Charlton, K., Lindsay, J., & Greathouse, S. (1996). The effects of summer vacation on achievement test scores: A narrative and meta-analytic review. Review of Educational Research, 66(3).

Dam, A. (2004). The 4-day school week. Retrieved on July 27, 2006, from the Colorado Department of Education:

Farbman, D. & Kaplan, C. (2005). Time for a change: The promise of extended-time schools for promoting student achievement. Boston, MA: Massachusetts 2020.

Graham, M. G. (Ed.). (2000). Sleep needs, patterns, and difficulties of adolescents. Washington, DC: Forum on Adolescence, Board on Children, Youth, and Families, National Research Council, Institute of Medicine.

Harmston, M. T., Pliska, A. M., Ziomek, R. L. & Hackmann, D. G.(2003). The relationship between schedule type and ACT assessment scores: A longitudinal study. Retrieved on June 1, 2006, from ACT:

Irmsher, K. (1996). Block Scheduling. Educational Management, 104(March). Retrieved June 2, 2006, from ERIC Clearinghouse:

Kneese, C. (1996). Review of research on student learning in year-round education. Journal of Research and Development in Education. 29(2), 60-72.

Palmer, E. A. & Bennis, A. E. (1998). Year-round education. Retrieved on July 20, 2006, from

Tonn, J. L. (2006). Later high school start times: A reaction to research. Education Week, 25(28), 5, 17.

Wahlstrom, K. (2002). Changing times: Findings from the first longitudinal study of later high school start times. Retrieved on June 26, 2006, from Center for Applied Research and Educational Improvement, College of Education and Human Development, University of Minnesota:

Walberg, H. J. (1998). Uncompetitive American schools: Causes and cures. In Ravitch, D. (Ed.), Brookings Papers on Education Policy (pp. 173-205). Washington, DC: Brookings Institution.

Walston, J. T. & West, J. (2004). Full-day and half-day kindergarten in the United States: Findings from the early childhood longitudinal study, kindergarten class of 1998-99. Retrieved on June 16, 2006, from National Center for Education Statistics:

Yarbrough, R. & Gilman, D. A. (2006). 4 days a week. American School Board Journal, 193, 43-45. Retrieved on July 10, 2006, from National School Boards Association:

Reprinted from the Center for Public Education,'Brien, E.M. (2006). Key Lessons: What Research Says About Reorganizing School Schedules. Washington, DC: Center for Public Education.


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