Best Public Holiday APIs for Developers in 2026

Public holiday data sounds simple until you actually need it: every country has its own list, regional variations matter, and the data changes year to year. This shortlist covers the free APIs that handle the hard parts for you, so you can ship calendar-aware features without curating dates by hand.

Quick comparison

What "free" actually means here

For a holiday API to qualify:

• It must work without an API key or paid plan.
• It must publish the data in a stable, machine-readable format.
• It must cover at least one full country, not just a handful of dates.

All four APIs on this list pass that bar comfortably and have been used in production by HR systems, scheduling tools, and SaaS apps for years.

API options

Nager.Date

Nager.Date is the default starting point for global holiday coverage. It serves 100+ countries with a consistent response shape, includes long weekend computation, and explicitly advertises no authentication and no rate limit.

Use it when:

• You are building a SaaS product that needs holiday data for many countries.
• You want a single API with a stable response shape.
• You don't want to deal with rate limits or keys.

This is the API most calendar, HR, and scheduling tools end up using.

OpenHolidays API

OpenHolidays covers public holidays plus school holidays across European countries. The school-holiday coverage is the differentiator — most APIs stop at official public holidays.

Use it when:

• You are building a European-focused product.
• You need school-holiday data (parent apps, family travel, e-learning).
• You want both public and school holidays from a single source.

Outside Europe the coverage thins out, so pair it with Nager.Date if you need global reach.

UK Bank Holidays API

UK Bank Holidays is the official GOV.UK JSON feed at /bank-holidays.json. It covers England & Wales, Scotland, and Northern Ireland separately, returning all historical and future holidays in one request.

Use it when:

• You are building a UK-focused product where regional accuracy matters.
• You want the official source rather than a third-party aggregation.
• You need a single-request feed that you can cache for the year.

For UK-specific work this is the canonical source — every UK payroll and HR vendor pulls from this feed or a derivative.

isDayOff

isDayOff is purpose-built for one question: "is this date a working day?" Coverage is Russia, Ukraine, Belarus, and Kazakhstan. The API returns a single bit per date, which makes it ideal for payroll and scheduling logic.

Use it when:

• Your product targets users in Russia or CIS countries.
• You need a working-day-aware date math primitive.
• You want the simplest possible response: 0 (working) or 1 (off).

For broader coverage, Nager.Date can answer the same question by checking whether the date matches a holiday in its list.

Picking the right one

Match the API to the product:

• Global SaaS → Nager.Date.
• European product, school holidays needed → OpenHolidays.
• UK-specific product → UK Bank Holidays.
• Russia / CIS product → isDayOff.

Most production systems combine two of these — for example, Nager.Date for global coverage and UK Bank Holidays for the UK-specific accuracy.

When not to use these APIs

These APIs are excellent free options, but they are not the right fit when you need:

• Custom corporate holiday calendars. Public APIs only cover official public holidays. Company-specific PTO and observances are your own data.
• Real-time changes mid-year. Holiday lists are stable but governments do occasionally add or move dates. Build in a refresh cycle rather than caching forever.
• Non-Gregorian calendar accuracy at scale. For Hijri or other lunar calendars, use specialized prayer-time or religious-calendar APIs instead.

Related API Deposu entries

• Nager.Date
• OpenHolidays API
• UK Bank Holidays API
• isDayOff API

Sources

• Nager.Date Swagger
• OpenHolidays API Swagger
• UK Bank Holidays JSON feed
• isDayOff API documentation