About Persian Calendar

A useful calendar, with room to explore

Persian Calendar Online is a free, English-first reference for the Persian calendar, also called Jalali, Shamsi or Solar Hijri. You can check a date, convert it to or from Gregorian, explore the twelve months, and read about celebrations and Khayyam’s poetry.

The calendar and converter work without an account. The site also offers documented, read-only date tools for developers and compatible assistants.

How the date calculation works

The converter uses jalaali-js, an open-source implementation of Jalali calendar arithmetic. The website, JSON API and agent tools share that calculation engine. Gregorian month lengths, century leap years and Persian Esfand length are validated before conversion; impossible dates are rejected.

A civil date is a year, month and day. Converting it does not change its timezone. Calculating today does depend on location: the interactive calendar follows your device’s local date, and the API accepts an explicit timezone such as Asia/Tehran.

The public API accepts Gregorian input years 1800–2200 and Persian input years 1280–1600. The interactive converter retains a broader historical range. Arithmetic calendar rules should not be treated as a substitute for an official calendar or an astronomical observation.

Nowruz, celebrations and holidays

Nowruz connects the Persian year with the spring equinox. This site converts 1 Farvardin to a Gregorian civil date; it does not calculate the exact equinox instant. For an event time, use an astronomical source and specify the timezone.

Celebration guides use the Persian month and day stored in this site’s cultural collection. Calendar traditions and local observances may differ. The calendar’s holiday highlighting and the API’s legacy isHoliday field include cultural dates and Fridays; they are not a complete or verified list of legal public holidays.

Gregorian ranges in the month introductions describe the usual season. For an exact year, use the converter or the month-boundary tool.

Reading and sources

Calendar implementation details are available in the jalaali-js source and documentation. The United Nations’ International Day of Nowruz reference provides further cultural context.

The site’s existing Khayyam collection can be browsed through verse themes and permanent quatrain pages. For a reproducible reference, link to the individual poem rather than a changing daily destination.

Privacy and access

Read the privacy policy for the site’s analytics and data handling. Calendar APIs require no login, personal details or payment. The developer guide explains the actual endpoints, accepted inputs and errors.