Knowra Persian calendar Persian calendar The Persian calendar is a solar calendar used in Iran and Afghanistan, with its year beginning at the March equinox. Its months track the seasons more closely than fixed-length civil calendars.
March equinox : The moment when the Sun crosses the celestial equator northward, occurring around March 20 or 21. The calendar’s year begins at the equinox, determined by astronomical observation or calculation.
Zoroastrian calendar : A family of calendars used by Zoroastrian communities, with distinct regional systems and religious observances. Zoroastrian timekeeping shaped traditions surrounding the Persian year and its festivals.
Islamic calendar : A lunar calendar of twelve months whose year is about eleven days shorter than the solar year. Unlike the Persian calendar, it drifts through the seasons.
Iranian date conversion : The conversion between dates in the Iranian Solar Hijri calendar and dates in other calendar systems. It handles the calendar’s equinox-sensitive year boundary.
Solar year : The time Earth takes to complete one orbit relative to the seasons, about 365.2422 days. The calendar approximates this seasonal cycle rather than following lunar phases.
Jalali calendar : A solar calendar introduced under the Seljuk ruler Malik-Shah in the eleventh century, associated with Omar Khayyam’s reform. Its equinox-based rule became a major precedent for the modern Persian calendar.
Gregorian calendar : The internationally used civil calendar, based on a 365-day year with leap-year corrections. Both are solar calendars, but their year starts and leap-year rules differ.
Afghan date conversion : The conversion between Afghan Solar Hijri dates and dates in other calendar systems. Afghan civil records use the same seasonal calendar with local conventions.
Persian calendar months : The twelve named months of the Persian calendar, with the first six lasting 31 days and the next five 30. Their unequal lengths organize the year between successive equinoxes.
Omar Khayyam : A Persian mathematician, astronomer, and poet associated with the eleventh-century Jalali calendar reform. His astronomical expertise helped establish the reform’s reputation for precision.
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