School Calendar Research
There is no open dataset of American school calendars. They are set by roughly 13,000 individual districts and published as PDFs, which is why questions about them are so hard to answer at any scale. We assemble the data by hand, district by district, from official sources — and these pages report what it shows.
Each analysis states its sources and its limits. The dataset is a deliberately narrow one, and the findings are written to describe it rather than the country.
Analyses
- How Much Do U.S. School Calendars Actually Differ?
An analysis of 16 large U.S. school districts enrolling 3.6 million students: their 2027 spring breaks fall across six different weeks, and in three of four states the districts do not agree with each other.
- School Calendar Laws by State: Start Dates and Required Instructional Time
Which U.S. states set school start and finish dates in law, and how many days or hours each state requires — a 50-state table with statutory citations, and what it explains about why calendars differ.
The underlying data
District calendars are transcribed from each district’s own published calendar with the source cited on the page. Browse them from the state and district directory.