Precise, structured, LEA-level school calendar data for the United Kingdom.
A Local Education Authority (LEA) is the local government body responsible for state-funded education in its area. In the UK, school term dates and holidays are not set nationally — they are determined independently by each LEA. This means half term in Birmingham can fall a week earlier than in Manchester, and Easter break in Cardiff may differ entirely from Edinburgh.
For any business whose demand is driven by school holidays, that variation is the signal. Semestern structures all 208 LEAs across four UK nations into a single consistent dataset so your team can query, filter, and model on the actual break timing — not a national approximation.
Every local education authority in England, Wales, Scotland, and Northern Ireland — structured to a single consistent schema.
The historical dataset covers every academic year from 1996–97 through to the current year. Every record follows the same schema — so querying half term dates in 1998 uses the same API call as querying 2025.
Run your demand model against 28 years of actual break timing to validate assumptions before going live.
Identify which LEAs have moved their half terms and by how much, across the full historical series.
Cross-reference historical holiday dates with pupil population to weight regional demand signals accurately.
Build ML training datasets with labelled school holiday windows at LEA granularity going back to 1996.
Map your transactional data to school year windows across all four nations simultaneously.
Decompose long-run seasonality components using a consistent 28-year holiday signal as a regressor.
Not all LEAs are equal. Greater Manchester has over 141,000 pupils; rural LEAs may have fewer than 10,000. Semestern includes pupil population data at the total and year-group level, enabling you to weight break periods by actual pupil volume rather than treating every LEA as equivalent.
Sources: Department for Education (England), StatsWales, Scottish Government statistics, Department of Education Northern Ireland — the same 28-year series as the holiday data.
Query by LEA, nation, school year, event type, or date range. Every response follows the same structure — across years, nations, and event types.
Full dataset updated each May with the following academic year's confirmed term dates, holiday windows, and INSET days for all 208 LEAs.
Some LEAs publish final amendments in July or August. These are captured in a supplementary update before the new academic year begins in September.
Occasional mid-year corrections (e.g. emergency school closures that become official INSET days) are patched quarterly. Enterprise customers are notified immediately.
Request access and we will send sample data for your region within one business day.
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