As district administrators know, there’s no one way to map the school calendar. Depending on where you live, the start of the school year may be set to coincide with the dog days of summer or the onset of fall. Across the districts in NCTQ’s Teacher Contract Database (TCD), there are 39 days between when the earliest and latest school years begin. While the range of starting dates is interesting, what may be of more consequence, given the connection between learning time and outcomes, is that the length of the school year can vary by as many as 17 days for students, and there can be up to a 20-day difference in the number of teacher workdays (days on the job without students) throughout the year.
To further explore the makeup of academic years, this District Trendline looks at the 2023-2024 calendar for 146 of the largest school districts in the United States1 to provide a snapshot of what the school year looks like for both teachers and students.2
The teacher school year
Before getting to the details, it’s important to define three categories of days for teachers:
- In-service: all days teachers are working, with or without students
- Instructional: in-service days spent teaching students
- Workdays: in-service days without students
Among TCD districts, teachers average 187 in-service days this year, matching what we found when looking at 2018-2019 calendars.3 At one end of the spectrum is Fairfax County Public Schools (VA), which requires teachers to work 195 days. At the other end is Toledo Public Schools with a 178-day year, falling nearly two weeks below the average.
Figure 1.
While teachers are ultimately employed to provide instruction, making the most of their time with students requires planning and preparation. As we reported last year, multiple surveys indicate that teachers desire more planning and collaboration time, and more time dedicated to planning and professional development is associated with greater student achievement (though there are some caveats).4
Large districts appear to be providing teachers with more time without students, with an average of 10.5 teacher workdays this year, an increase of a full day since 2018-2019. With the number of in-service days unchanged over the same time frame, districts have swapped one instructional day for an additional teacher workday. It’s important to note that workdays extend to include professional development and parent-teacher conferences, so the additional day may not translate into more planning time.
When looking at the distribution of teacher workdays, there is again a considerable range among districts. Teachers in
Sacramento City Unified School District only have a single day without students, while teachers in two North Carolina districts (Winston-Salem/Forsyth County Schools and Cumberland County Schools) each have 21 workdays this year.
Figure 2.
It would seem logical that districts with more total in-service days would also be those with the most teacher workdays, but that correlation is limited.5 Figure 3 provides a snapshot of ten TCD districts to highlight the varying ways in which teacher time is allocated over the year. Each one percentage point difference represents about two and a half days, meaning that while a general pattern holds across districts, there are meaningful differences. For example, the six percentage point gap between instructional days in Baltimore County Public Schools and Columbus City Schools represents a three-week disparity in class time.
To illustrate some other differences that can be seen when looking at only a handful of TCD districts, teachers in
Winston-Salem/Forsyth County Schools have 18 more workdays than teachers in Boston Public Schools,6 but seven fewer instructional days. In other words, comparatively, teachers in Winston-Salem are contracted to be on the job more, but spend fewer days teaching. In another example, while teachers in Albuquerque Public Schools have the second-fewest number of instructional days among the districts in Figure 3, they also have the second-shortest summer break as a result of the district scheduling a large number of workdays and vacation days throughout the year. In a similar vein, the number of extended breaks leave teachers in El Paso Independent School District with more time off during the year than over summer break.
Figure 3.
The student school year
Numerous studies have found an association between students’ learning time and their achievement.7 To that end, the average district in the TCD sample has 177 student school days this year. As previously noted, this is one day less than districts required in 2018-2019. However, both now and then, 180 days stands as the most common duration across districts.
Matching what we first
found over a decade ago, two Maryland districts (Baltimore County Public Schools and Anne Arundel County Public Schools) have the longest school years with 183 instructional days, a count also shared by Los Angeles Unified School District. In contrast (and also matching our 2013 findings), Tulsa Public Schools has 166 days of instruction, tied for the fewest with Cumberland County Schools in North Carolina. These two districts are joined by ten others that fall at least two weeks short of 180 days of instruction.
Figure 4.
Of course, districts typically don’t determine the number of days students are required to report independently. State laws and funding often compel districts to maintain a minimum number of instructional days. It’s similarly important to note that this analysis is limited to the count of days and does not consider the
length of each school day, which may balance the amount of time students are in school.
When looking at the 23 states with
at least two districts in the TCD, the effect of state policy can be seen in Figure 5. Districts in Indiana, Mississippi, and South Carolina all come in at exactly 180 days of instruction, the minimum set in those states. The effect of lower state minimums is evident in Colorado, where districts are permitted to have as few as 160 days, and in both Minnesota and Oklahoma, which allow districts to operate with 165-day calendars.
Figure 5.
The most common minimum set by states is 180 days; however, several states with that minimum contain districts that fall short.8 It is worth noting that the methodology employed for our counts treats all partial and remote learning days as full days. In other words, our approach is more likely to overestimate the number of days than undercount them, meaning that the disconnect between state minimums and 2023-2024 calendars is likely due to what states permit districts to include toward the 180-day total. One such example received news coverage earlier this year when the New York City Department of Education reduced the school year to 178 days and was allowed to count teacher training days towards the state minimum of 180.
While looking at student school years across the country, we took note of the number of extended breaks throughout the year—those at least one week in duration—and here again, there are considerable differences between districts. Excluding winter vacation, for which students in all TCD districts are off for at least a week starting in December, students have as many as four additional one-week breaks9 and as few as none.10 The most common structure used by nearly three in five districts is to give students a week off in both the fall (either in October or late November) and again in the spring.
Looking only at December winter breaks across TCD districts, some students had three full weeks off this year, while others received only a six-day break. We see a general pattern where districts in northeastern states take less time off than the national average, while those in southern and western states typically take more.
Figure 6.
What didn’t we see?
While four-day school weeks may be spreading in some more rural parts of the country, we saw no evidence of them in the larger and predominantly urban and suburban districts included in the TCD sample. This is good news, since studies call into question whether shorter weeks offer any benefits to students and teachers in urban districts.
There appears to be limited use of asynchronous learning days for students. Only 12 districts in our sample (8%) have at least one virtual day for students. These days typically coincide with professional development days for teachers, but also appear on days of parent-teacher conferences and elections. Interestingly, all seven Georgia districts in the TCD have one or more asynchronous days, and three of the six Maryland districts in our sample do as well. In other words, the current inclusion of virtual days for students may be more of a trend within states than across them.
What’s the best approach?
There’s no one right way to develop the school year calendar. Districts have to find a schedule that works best for their community after considering the tradeoffs. For example, is it better to have a longer summer break or more time off during the school year? Should additional teacher workdays be added to the calendar at the cost of time for student instruction? Will parents support an additional week of instruction to offset their need to find caretakers over the summer? Is it worth increasing teacher salaries (and the district budget) to teach an additional week each year? There are no simple answers to these questions, but the conversations should take full consideration of the research. While there’s no magic number of school days, the evidence is clear that students need time in school to learn, and teachers need time to plan and prepare.
More like this

Think a four-day school week is better? Think again
A four-day work week may seem like a good way to attract teachers and address tightening school budgets, but researchers say it might do more harm than good.

Teacher salaries, cost of rent, and home prices: Can teachers afford to live where they teach?
Lack of affordable housing exacerbates the teacher staffing challenges that many school districts face.

Planning time may help mitigate teacher burnout—but how much planning time do teachers get?
A look at how the nation’s largest districts address planning and collaboration time for elementary and secondary teachers
Endnotes
- The sample for this analysis, drawn from NCTQ’s Teacher Contract Database, consists of 148 school districts in the United States: the 100 largest districts in the country, the largest district in each state, and the member districts of the Council of Great City Schools. Because of the adjustments made to the Portland (OR) Public Schools calendar due to teacher strikes this year, calculations were made using the district’s 2022-2023 calendar. NOLA Public Schools and Cleveland Metropolitan School District are excluded from the findings due to unclear dimensions of teachers’ academic year, reducing the district count to 146.
- Where there are differences between the academic calendar, this analysis defaults to what is used for elementary teachers and students.
- Comparisons between 2018-2019 and 2023-2024 calendars are based on 142 districts that appear in both samples. The six districts in the current TCD sample that were excluded are Aurora Public Schools (CO), Champlain Valley School District (VT), Cleveland Metropolitan School District, Forsyth County Schools (GA), NOLA Public Schools, and Round Rock ISD (TX).
- This was the finding of a meta-analysis, though the vast majority of studies analyzed did not meet the methodological requirements to be included in the analysis. Yoon, K. S., Duncan, T., Lee, S. W. Y., Scarloss, B., & Shapley, K. L. (2007). Reviewing the evidence on how teacher professional development affects student achievement. issues & answers. rel 2007-no. 033. Regional Educational Laboratory Southwest (NJ1). Note that other research has found that professional development specifically is often ineffective: Jacob, A., & McGovern, K. (2015). The mirage: Confronting the hard truth about our quest for teacher development. TNTP.
- The correlation coefficient between in-service days and teacher workdays is 0.385.
- Teachers in Winston-Salem/Forsyth County Schools have 21 in-service days without students in 2023-2024,
while teachers in Boston Public Schools have three.
- Farbman, D. A. (2015). The Case for Improving and Expanding Time in School: A Review of Key Research and Practice. Updated and Revised February 2015. National Center on Time & Learning. https://www.timeandlearning.org/sites/default/files/resources/caseformorelearningtime.pdf
- Alabama, Georgia, Nevada, New York, Tennessee, Utah, and Virginia. TCD districts in North Carolina also fall short of 180 days despite the state setting a 185-day minimum.
- Aldine Independent School District (TX), Atlanta Public Schools, Birmingham City Schools, Cobb County School District (GA), and Klein Independent School District (TX).
- Bismarck Public Schools (ND) and Sioux Falls School District (SD).