Hebrew Calendar Explorer

Now with Sky Events: moon phases, traditional full moon names, and solar and lunar eclipses computed for your own location, alongside the feasts and Torah readings.

Hebrew Calendar Explorer is a teaching tool for the fixed rabbinic Hebrew calendar, written for pastors, Bible teachers, Sunday-school leaders, and seminary students.

Most Hebrew calendar apps are built for Jewish observance. This one is built to help you understand and teach the system — the arithmetic behind the dates, not just the dates themselves.

EVERY DATE IS VERIFIED TWICE Two independently derived calendar engines compute every date. Before a single date is shown, the app reproduces 21 independently published Rosh Hashanah dates, checks both engines against each other year by year, confirms every year length and month table, and runs round-trip conversions in both directions. If any check fails, the app shows an error rather than a date. The full 689,472-year repeat cycle of the calendar has been verified and archived publicly.

WHAT'S INSIDE • Calendar — month by month, with Hebrew and civil dates side by side, feast days, Torah portions, and moon phases • Year Explorer — the whole Hebrew year at a glance, with a printable year poster • Convert Dates — Gregorian to Hebrew and back, including proleptic dates • Feast Guide — the appointed times of Leviticus 23 in calendar order • Day by Day — every observance of the year in sequence, with the fast deferral rules applied • Torah Readings — the annual cycle, with the doubling rules resolved • Sky Events — moon phases, traditional full moon names, and solar and lunar eclipses, with local visibility from where you are • Teacher's Guide — how the calendar works, then six chapters on teaching it, each ending with an activity you can verify in the app • Research — molad traces, interval analysis, and full calculation workings for any year • About & Sources — what is claimed, what is not, and where it comes from

BILINGUAL The entire app runs in English or Hebrew, including full right-to-left layout. Switch at any time from the header.

ON YOUR DEVICE • Today and Lock Screen widgets • Apple Watch app with complications • Add feasts and your own events to your device Calendar • Reminders with alerts • Sunrise, sunset, solar noon and midnight for your location, and for Jerusalem • Four colour themes

PRIVATE BY DESIGN No accounts. No sign-in. No analytics. No tracking. No advertising. Your events, reminders and settings stay on your device — there is no server holding them. Location is optional, used only to calculate times where you are, and never sent to us.

FREE The app is free and will stay free. There are no subscriptions, no in-app purchases, and no ads.

ABOUT THE AUTHOR Richard J. Allinson is a Bible teacher and the author of The Final Seven Years. The calendar engines and their verification records are published openly on Zenodo.