Hebrew Calendar vs The Calendar

Hebcal converts between Gregorian and Hebrew dates and computes Shabbat start/end times, holiday dates, Torah readings, and the Daf Yomi study cycle for any location, driven by the same open-source engine (@hebcal/core) that runs the hebcal.com website. Every endpoint is keyless JSON (or RSS/iCal on other routes) under a Creative Commons Attribution 4.0 license, so results can be reused commercially as long as Hebcal is credited. It's rate-limited to keep the free service polite — no more than 90 requests per 10-second window — and the once-http-only backend now serves over HTTPS as well.

The Calendar publishes pre-generated, static JSON (and downloadable .ics) files for US federal and all-50-state holidays (2025–2028), 30 countries' public holidays, plus FOMC meeting dates, US tax deadlines, market holidays, and key-date calendars for a dozen sports leagues. Every one of its 99 documented endpoints is a flat file behind Cloudflare, so there's no authentication, no rate limit, and CORS is wide open — licensed CC BY 4.0 as long as you link back.