About All Calendars Now

All Calendars Now shows a single instant — right now, where you are — as it reads on 56 different calendars at once, arranged into 10 families: the living calendars of faith and state, the cyclical and seasonal reckonings that count no years at all, the counts machines keep, deliberate reforms that mostly failed, and the calendars of imagined worlds.

How it works

Everything is computed live in your browser, ticking each second, in your own time zone. The living calendars — Hebrew, Islamic, Persian, Chinese, Ethiopian and the rest — come straight from your browser’s own internationalization engine (ICU), so they match your operating system exactly. The historical, indigenous, invented and fictional reckonings are computed from published formulas.

What is exact, and what is estimated

Most dates here are exact. A handful are, by their nature, approximate, and each says so on its page: the French Republican and Baháʼí years are timed to the astronomical equinox; the Maya and Aztec counts rest on the standard GMT and Caso correlations. Where a fictional world sets its year-zero in our own future or deep past, today is placed accordingly — Dune reads deep Before Guild, Star Wars far After Yavin — and those anchors are clearly labelled estimates, since no canon dates these worlds against Earth. The fictional calendars are here for interest, not as claims of fact.

One principle

A second is a second everywhere. We never speed a clock up to force its day to end at our midnight. So a world whose day or year is a different length simply drifts against ours — Roshar’s twenty-hour day, the slightly shorter sidereal day — which is the honest result and, we think, the more interesting one.

Sources

The calendar algorithms follow standard references — chiefly Dershowitz and Reingold’s Calendrical Calculations and the astronomical methods of Jean Meeus — together with each tradition’s own scholarship and, for the invented and fictional calendars, their primary sources and canon. The glossary explains the ideas the calculations rest on, and the sources and acknowledgements page credits every source in full.

Privacy

The site collects nothing about you. There are no accounts, and nothing you do here is stored — the one form, on the report page, simply emails us what you write. Your location, if you choose to share it for sunrise and sunset, is used only on your device and never sent anywhere. See the privacy policy for the full, short story.

Who made this

All Calendars Now is a project of Epiqara, a small studio building a family of tools and sites. If you find an error in a calculation or a calendar you think belongs here, we’d like to hear it — write to hello@epiqara.com. You might also like our other work: Loadout Match and The Outdoor Dispatch.