Persian calendar

Persian calendar. The Persian calendar is a solar calendar with ancient roots, now officially used in Iran and Afghanistan. It is one of the world's most accurate calendar systems, aligning closely with the tropical year. Its modern iteration, the Solar Hijri calendar, was codified in the 20th century and begins its epoch with the Hijra of the Islamic prophet Muhammad.

History and origins

The calendar's origins trace back to the Zoroastrian calendar reforms during the Achaemenid Empire, influenced by earlier Babylonian and Egyptian systems. It was profoundly refined during the Sasanian Empire under rulers like Khosrow I, incorporating precise astronomical observations. After the Muslim conquest of Persia, the Islamic calendar was introduced for religious purposes, but the solar calendar persisted for agriculture and taxation. The modern form was established by the Iranian Parliament in 1925, based on the calculations of astronomers like Omar Khayyam, who worked during the reign of the Seljuk Empire's Malik-Shah I.

Structure and features

This is a solar calendar based on the Earth's revolution around the Sun, with the New Year beginning at the precise moment of the March equinox in Tehran. A year consists of 12 months, with the first six having 31 days, the next five having 30 days, and the final month having 29 or 30 days in a leap year. The leap year system, a sophisticated intercalation method, adds one day approximately every four years to maintain alignment with the tropical year, a system more accurate than the Gregorian calendar's. The calendar week begins on Saturday, and each day is dedicated to a Zoroastrian divinity.

Months and festivals

The months have preserved their ancient Avestan names, such as Farvardin, Ordibehesht, and Khordad. The most important festival is Nowruz, the New Year celebration centered on the March equinox, with roots in the Zoroastrian tradition and recognized by UNESCO. Other significant observances include Mehregan in the month of Mehr, celebrating Mithra, and Tirgan in Tir, associated with the archangel Tishtrya. The month of Mordad is linked to concepts of immortality, while Bahman represents good purpose. The final month, Esfand, includes the festival of Sepandarmazgan.

Comparison with other calendars

Unlike the purely lunar Islamic calendar used for religious events like Ramadan, it is a solar system, causing its year to start about 11 days earlier relative to the Gregorian calendar each cycle. Its epoch, the Hijra, is shared with the Islamic calendar, but it counts solar years, making the year number larger. Its mathematical precision, derived from the Malik-Shah reforms, often makes it more astronomically accurate than the Julian calendar and even the Gregorian calendar over long periods. It differs from the Chinese calendar by being purely solar rather than lunisolar.

Modern usage and variants

It is the official civil calendar of Iran, used in all government documents, media like the Tehran Times, and daily life, and is recognized in Afghanistan as the Solar Hijri calendar. The Kurdish people also utilize it culturally. In Iran, it coexists with the Islamic calendar for religious observances such as Muharram. Minor computational variants exist, such as the Jalali calendar algorithm used in software libraries. Its New Year, Nowruz, is widely celebrated across regions from the Balkans to Xinjiang, and its influence is seen in historical empires like the Mughal Empire and the Ottoman Empire.

Category:Solar calendars Category:Iranian culture Category:Calendars