Calendar APIs provide holiday data, date calculations, and scheduling functionality. Build event planners, booking systems, or simply display upcoming holidays for any country.
Last verified: November 12, 2026
| Name | Description | Auth | HTTPS | CORS | Uptime (30 days) |
|---|---|---|---|---|---|
| Africa Compliance Data | Public holidays and business days for all 54 African countries, from official sources | apikey | Yes | yes | 100% (5 checks) |
| Business Box | Booking API for small businesses in Japan: event types, open slots, bookings, invite links and webhooks, with API keys on the free plan | apikey | Yes | yes | 100% (5 checks) |
| caldays | Public holidays for 195+ countries | none | Yes | yes | 100% (5 checks) |
| Checkiday - National Holiday API | Industry-leading Holiday API. Over 5,000 holidays and thousands of descriptions. Trusted by the World’s leading companies | apikey | Yes | unknown | 100% (5 checks) |
| Church Calendar | Catholic liturgical calendar | none | No | unknown | 100% (5 checks) |
| CountdownsHQ | Dates and timezone-correct countdowns for 150+ holidays and observances in 18 countries | none | Yes | yes | 100% (5 checks) |
| DigiDates | Various date and time calculations | none | Yes | yes | 100% (5 checks) |
| Festivo Public Holidays | Fastest and most advanced public holiday and observance service on the market | apikey | Yes | yes | 80.0% (5 checks) |
| Generate iCAL | Generates iCal calendar events that can be used across calendar applications | apikey | Yes | yes | 100% (5 checks) |
| Google Calendar | Display, create and modify Google calendar events | oauth | Yes | unknown | 100% (5 checks) |
| Hebrew Calendar | Convert between Gregorian and Hebrew, fetch Shabbat and Holiday times, etc | none | No | unknown | 100% (5 checks) |
| Holidays | Historical data regarding holidays | apikey | Yes | unknown | 100% (5 checks) |
| India Public Holidays | Official Indian public holidays for the Central government and 36 states/UTs | none | Yes | yes | 100% (5 checks) |
| Intellibook | Appointment booking and availability API for salons and clinics | none | Yes | yes | 100% (5 checks) |
| Mother's Day Calendar | Mother's Day dates, country rules, sources and confidence as static JSON and CSV | none | Yes | yes | 100% (4 checks) |
| Non-Working Days | Database of ICS files for non working days | none | Yes | unknown | 100% (5 checks) |
| OpenHolidays API | Public and school holidays for many countries via an open REST API | none | Yes | yes | 100% (5 checks) |
| Public Holidays | Data on national, regional, and religious holidays via API | apikey | Yes | yes | 100% (5 checks) |
| Russian Calendar | Check if a date is a Russian holiday or not | none | Yes | no | 100% (5 checks) |
| The Calendar | Public holidays for US states and 30 countries plus sports and finance calendars as static JSON | none | Yes | yes | 100% (5 checks) |
| UK Bank Holidays | Bank holidays in England and Wales, Scotland and Northern Ireland | none | Yes | unknown | 100% (5 checks) |
13 of these APIs require no authentication — you can start making requests immediately without signing up for an account. Just pick one from the table above, check its documentation, and send your first request.
7 APIs in this category require a free API key. This usually means creating a free account on the provider's website and copying your key from the dashboard. The process typically takes less than a minute.
Not sure where to start? Check the uptime column: it shows how often each API's documentation responded to our daily checks over the last 30 days, and the dot shows whether it responded at the latest check. For browser-based projects, check that the API supports CORS.
Yes, all APIs listed on API Bouncer have a free tier. Some are completely open (no sign-up needed), while others require a free account to get an API key. Free tiers typically have rate limits — check each API's documentation for specifics.
It depends on your needs. Consider: Do you need authentication or prefer no-auth? Does your project need CORS support for browser access? How many requests will you make? Start with a no-auth API to prototype quickly, then switch to a more feature-rich option if needed.
We run periodic health checks on all listed APIs. The "Status" column shows whether each API was responding at our last check. APIs marked as "alive" were recently verified. You can also test any API yourself using curl or our guides on testing APIs.
Most free APIs allow commercial use, but terms vary by provider. Always check the specific API's terms of service. Some APIs have separate free and commercial tiers with different rate limits.
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