Less is More: Shifting to a Trimester Schedule

Guest post by Britton Hart

We had a problem at Emporia High School—failure rates were going up but the time and money available to address student needs stayed the same. For several years, there had been a steady increase in economically disadvantaged and ELL populations. Our leadership team needed to find a solution using existing resources that helped us address the educational challenges of our evolving student population.

To meet these challenges, we decided to move from a traditional block schedule to a new trimester system for the 2016–17 school year. The trimester system has provided us a way to create a master schedule that better addresses the current needs of our students.

What is a Trimester Schedule?

In general, a trimester system makes three significant changes to the master schedule. First is the way the school year isstructured. Instead of quarters or semesters, the school year is divided into three 12-week trimesters. Second, there is a reduction of the number of overall class periods. Trimester schedules usually run five class periods that meet every day; block schedules run eight classes (four classes per day that meet every other day) for one semester. Third, the trimester schedule offers varying course lengths. Typically, core classes are two trimesters, or 24 weeks; electives are one trimester, or 12 weeks; and some special classes such as AP and music, are all three trimesters, or 36 weeks.

Benefits of a Trimester Schedule

The trimester schedule has numerous advantages for our students and staff. The first, and perhaps most important, benefit is increased instructional time. Look at this comparison of our previous block schedule and the new trimester schedule for a core class:


Block Schedule Trimester Schedule
Course length Yearlong (174 days) Two trimesters (118 days)
Number of class periods 87 class periods 118 class periods
Block length 83 minutes 72 minutes
Total number of minutes 7,221 minutes 8,496 minutes

Despite meeting for only 24 weeks, the trimester adds an additional 31 classes and 21 instructional hours, which is a substantial increase. This extra time has provided our students more frequent interaction with their core teachers, which was a struggle for us with our block schedule. Another benefit of the trimester schedule is that it has allowed us to embed academic interventions within the school day as part of our RTI process. Intervention takes place during the last 20 minutes of the block twice a week.

Other benefits of the trimester schedule:

  • Students are able to focus on fewer core classes at a time (three or less).
  • Students can repeat a class in the next trimester if needed.
  • Students can maintain sport participation eligibility each of the three trimesters versus just two semesters. Eligibility mirrors the seasonal schedule for sports and other activities.
  • Teachers have fewer students and classes to manage at one time.

Challenges of Switching to a Trimester Schedule

As we considered making the switch to a trimester schedule starting back in 2012, we faced a number of challenges; one of the most significant was trying to overhaul our scheduling program. We use Powerschool to schedule all of our classes, and it took a tremendous amount of time to ensure the new schedule accommodated all of the students’ requests. Another challenge was getting staff buy-in and changing their mindset. Teachers had to overhaul course curriculums to fit the trimester system, requiring some classes to add instructional content and others to trim material. We devoted many professional development hours and in-service days to support this transition.

Results and Future Direction 

The second trimester is nearly complete, and our preliminary data indicates positive results. After the first trimester, we have already seen a reduction in failure rates and we look forward to seeing if this trend continues for the second trimester. Students and staff have been largely positive about the switch and see many benefits to it. The trimester schedule has allowed our students to focus more intently on fewer subjects and has provided students and staff needed time for academic interventions. At EHS, we are doing “more with less” thanks to a trimester schedule.

Could a trimester schedule improve your school’s capacity to meet student needs?

To learn more about trimester schedules, visit Mark Westerburg’s website, School Improvement Using the 3 x 5 Trimester Schedule.

Britton Hart is the 2016 Kansas Principal of the Year. He is completing his 17th year in education, with 12 of those years serving as a building principal and athletic director at the high school level. He is most comfortable working in diverse, high-poverty schools supporting positive change to close the achievement gap for all students.


  • Michael Thomas says:

    Britton, how long did it take you to make a decision to switch to a trimester schedule, and what sorts of concerns were raised about the switch? Did you have difficulties convincing others about making the change?

  • Britton Hart says:

    All great questions Mr. Thomas. The process to change from a block schedule to a new trimester system took several years of planning and dicsussion with all stakeholders. The decision was made with how it would benefit our students!
    Thanks for your question,

  • What resources would you recommend for teachers to shift from teaching in a traditional 44-minute period to a 65-minute trimester class period?

  • Mr. Smith says:

    I really like this system, I hope we can implement it in my school district (Pasadena Unified).

  • Greetings Dr. Hart,
    Q#1: How would trimesters affect performance based fine arts classes where limited numbers of concerts can be scheduled. For example, a student taking orchestra in the first and third trimesters would miss the winter concert. More importantly, the need for continuity and consistent practice would be disrupted, not so?

    Q#2: How do the schools that use the trimester schedule handle all of the 1/2 credits? What I mean is that each period meets three 60-day cycles earning a 1/2 credit per cycle. That means, for instance, a student could take Geometry in the first two cycles and then has a period with an extra 1/2 credit to take. Do they allow students to accelerate and take the first semester of the next year or do they make them take a 1/2 credit elective

  • James Osborn says:

    Independence HS was the first to use the trimester system called Project Tri implemented in 1992 in Columbus City Schools. Our schedules used 12 week blocks of instruction and the day consisted of 3 two hour classes. A student could earn a Carnegie unit of credit in a 12 week 2 hour block. Grades were determined by 4-three week grading periods and a final exam. We repeated this 3x per year and experienced tremendous success for a Ten year period. We were featured in the 1994 National commission time and Learning report on “Prisioners of Time”.

  • Bill says:

    In my daughter’s trimester-based high school, they typically get a core class (like Math classes) only 2 of the 3 trimesters. This leave me wondering, when it comes to College Entrance Criteria, do colleges think of 2 trimesters of Math being the same as 2 semesters? Or will she be at a disadvantage to the semester-based kids, since the more elite colleges usually recommend “4 years of high school math”

    • Mona says:

      I went to high school in the trimester system and took two semesters/year of English, Social Studies, Math, and Science, and I still got into top schools. College admissions, from what I’ve gleaned, understand that ultimately the same amount of knowledge is being imparted in two trimesters as two semesters.

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