Public holidays for 199 countries and their regions, plus working-day checks, add-working-days and working-days-between that respect each country's weekend.
The Public Holidays API gives you the holiday calendar for 199 countries and thousands of states and regions, for any year from 1900 to 2100, including moving holidays such as Easter and substitute days such as Boxing Day moved to Monday. /check says whether a date is a working day, a weekend or a holiday. /add returns the date N working days after or before a start date, skipping weekends and holidays (delivery dates, SLAs, due dates). /between counts working days between two dates (payroll, billing). Weekends follow the country (Friday-Saturday in Saudi Arabia and Egypt, Saturday only in Nepal) and can be overridden. Countries and regions accept codes or English names. Holiday types: public, bank, school, optional, observance. Data from the open-source date-holidays rules, computed locally.
https://apistack.online/api/data/public-holidays/v1data