Calendar – Free-tier APIs
16 Free-tier APIs in the category Calendar. Free public web APIs that developers and AI agents can call. Entries come from the open public-apis list; each link was checked automatically (HTTP status) on the date shown, which says the site responded, not that the API is good.
caldays
Public holidays for 195+ countries
Calendarific
Worldwide Holidays
Checkiday - National Holiday
Industry-leading holiday data with over 5,000 holidays and thousands of descriptions
Google Calendar
Display, create and modify Google calendar events
Hebrew Calendar
Convert between Gregorian and Hebrew, fetch Shabbat and Holiday times, etc
Holidays
Historical data regarding holidays
India Public Holidays
Official Indian public holidays for the Central government and 36 states/UTs
Intellibook
Appointment booking and availability API for salons and clinics
Nager.Date
Public holidays for more than 90 countries
Namedays Calendar
Provides namedays for multiple countries
Non-Working Days
Database of ICS files for non working days
Non-Working Days
Simple REST API for checking working, non-working or short days for Russia, CIS, USA and other
Public Holidays
Data on national, regional, and religious holidays via API
Russian Calendar
Check if a date is a Russian holiday or not
The Calendar
Public holidays for US states and 30 countries plus sports and finance calendars as static JSON
UK Bank Holidays
Bank holidays in England and Wales, Scotland and Northern Ireland