World Calendar 1900–2100

A perpetual, multi-tradition calendar

This calendar spans two centuries (1900 to 2100) and combines multiple data sources so you can plan family, business, and spiritual events across traditions:

• National holidays from the open Nager.Date dataset for 100+ countries.
• Christian moveable feasts (Easter, Good Friday, Ascension, Pentecost) computed locally using the Meeus/Jones/Butcher Computus algorithm — accurate for every Gregorian year.
• Islamic holidays from the free Aladhan Hijri calendar API (Eid al-Fitr, Eid al-Adha, Mawlid, Islamic New Year, Ramadan start).
• Hindu, Sikh, Jewish, Buddhist holidays from a curated dataset, with the Calendarific slot ready to plug in a paid key for full 200-year coverage.

When you're offline or a live API is rate-limited, the calendar transparently falls back to a bundled JSON dataset so you always see at least the major festivals.