About Timeyard

Timeyard is a free tool for converting dates both ways between the Gregorian calendar (known in Persian as Miladi) and the Iranian Solar Hijri calendar (Shamsi, also called Jalali). Type a date in either calendar and you get the matching date in the other, instantly. There is no account, no sign-up, and nothing to install — though you can add it to your home screen if you wish.

The problem it solves

Iran and Afghanistan use the Solar Hijri calendar for everyday and official life, while most of the world uses the Gregorian calendar. That gap creates small, recurring friction: working out a birthday in the other calendar, reading a date on an official document, checking when a historical event happened, or simply matching an appointment between two calendars. Doing the arithmetic by hand is fiddly and easy to get wrong, because the two systems start their years at different points and follow different leap-year rules. This tool removes the guesswork for both Persian speakers and English speakers.

How the conversion works

Under the hood, the converter uses jalaali-js, a well-established open-source library that implements the proven 33-year arithmetic cycle for the Solar Hijri calendar. This is the same algorithm trusted across many Persian-calendar applications. The result is then cross-checked against your browser's built-in Intl Persian calendar as a second opinion.

A few deliberate design choices keep the output reliable:

• Date-only model. The tool works with calendar dates, never timestamps, so time zones can never quietly shift a result by a day.
• Consistent-by-construction validation. A date is treated as valid only when both calendars accept it and its counterpart year falls inside the supported range — so you never see an answer the two calendars would disagree about.
• Wide supported range. Conversions cover Jalali years 1–1700 and Gregorian years 622–2322, which comfortably spans historical research and everyday dates alike.

To learn the underlying calendar rules, see the guides on Shamsi to Gregorian, Gregorian to Shamsi, the Persian months, and leap years in both calendars.

A note on the Persian calendar

The Persian year begins on Nowruz — 1 Farvardin — which falls around 20–21 March. The first six months (Farvardin to Shahrivar) have 31 days each, the next five (Mehr to Bahman) have 30, and the final month, Esfand, has 29 days, or 30 in a leap year. Leap years follow the jalaali-js arithmetic cycle rather than the simpler Gregorian rule, which is one reason manual conversion trips people up.

Privacy first, by default

The converter runs entirely in your browser. There is no server doing the maths, and no network request is made to convert a date. By default the app collects nothing, sets no cookies, and makes no third-party requests — your dates never leave your device. After your first visit it also works offline, so you can keep converting with no connection at all; see using it offline.

Advertising and analytics are entirely optional layers that are off by default. They run only if the site owner chooses to enable them and you consent; if that happens, third-party scripts would load and may set cookies. Full details are in the Privacy and Cookies pages.

Free and open to use

Timeyard is free, needs no account, and is built for real people who just need an accurate answer. If you have a question, the FAQ covers the common ones, and you can reach us via the Contact page. Ready to convert a date? Open the converter.