Iranian calendars facts for kids

The Iranian calendars or Iranian chronologies (Persian: گاه‌شماری ایرانی, Gâh Šomâriye Irâni) are a succession of calendars created and used for over two millennia in Iran, also known as Persia. One of the longest chronological records in human history, the Iranian calendar has been modified many times for administrative purposes. The most influential person in laying the frameworks for the calendar and its precision was the 11th century Persian polymath, Omar Khayyam. The modern Iranian calendar is the Solar Hijri calendar, currently the official civil calendar in Iran.

Nowruz, the Iranian New Year, begins at the midnight nearest to the instant of the northern spring equinox, as determined by astronomic calculations for the meridian of Tehran (52.5°E). Thus the calendar is observation-based, unlike the Gregorian calendar, which is rule-based. This equinox occurs on or about 20 March of the Gregorian calendar. The time zone of Iran is Iran Standard Time, UTC+03:30.

Exploring Ancient Iranian Calendars

The history of Iranian calendars goes back a very long time. The first signs of these calendars are from over 2,000 years ago. This was even before the prophet Zoroaster appeared.

The first complete calendar we know about belonged to the Achaemenid kings. They ruled Persia around 500 BC. Persians have always cared a lot about having a good calendar. They were among the first cultures to use a solar calendar. This means their calendar was based on the sun's movement. They preferred this over calendars based on the moon. The sun was a very important symbol in Iranian culture.

The Old Persian Calendar

Early Iranian writings show that people used a 360-day calendar. It was based on watching the sun. Days did not have special names. Months were divided into two or three parts, depending on the moon's phases.

There were twelve months, each with 30 days. Their names came from festivals or farming activities. Sometimes, an extra month was added. This helped keep the calendar in line with the seasons.

Here are the Old Persian months and what they meant:

There were also six important festivals called gahanbar. These were spread throughout the year. They marked different farming seasons.

The Zoroastrian Calendar

The first calendars based on Zoroastrian beliefs appeared later. This was during the Achaemenid period (650 to 330 BC). These calendars changed over time. However, the names of the months stayed mostly the same.

The large Achaemenid Empire needed a special Iranian calendar. So, one was created, similar to the Egyptian calendar. It had 12 months of 30 days. Each month was named after a yazata (a divine being or angel). Four days each month were for Ahura Mazda, the main god. Seven days were named after six important holy beings. Other days were named after things like Fire, Water, Sun, Moon, and different gods or concepts.

Here are the month names and their modern versions:

This calendar was very important for religious practices. It made sure that the names of gods were often spoken. This happened during every Zoroastrian worship. It also set the dates for festivals. For example, the Mehregan festival was on the Mithra day of the Mithra month.

In 538 BC, Cyrus the Great took over Babylon. The Babylonian calendar, which used both the sun and moon, was then used for everyday life. Later, the Zoroastrians adopted the Egyptian solar calendar. This calendar had 12 months of 30 days, plus five extra days. These extra days were placed just before Nowruz, the spring new year.

When Alexander the Great conquered Persia, the Seleucid dynasty began. They started dating events from their own era. Zoroastrian priests, who were no longer part of the royal court, created their own "Era of Zoroaster." They tried to figure out when Zoroaster lived. They mistakenly used a date from Babylonian records. This date was actually when Cyrus the Great conquered Babylon in 539 BC. The priests thought this was when Zoroaster's faith was revealed. They believed he was 30 years old then. So, 568 BC became known as his birth year. This date is still sometimes mentioned today.

Changes by Later Rulers

The Parthians, who ruled after the Seleucids, used a similar calendar. They started their era from 248 BC. Their month and day names were Parthian versions of the older Avestan ones.

When the Sasanid kings took over in AD 224, King Ardashir I changed the official calendar. He brought back the Zoroastrian calendar. This change also fixed the dates of the gahanbar festivals. They had slowly moved out of sync with the seasons. The new dates were placed eight months later. The five extra days, called epagomenai, were also moved.

This change caused a lot of confusion. People were not happy. The new extra days were even called "robber days." People started celebrating "Great Nowruz" on a different day. This was Zoroaster's birthday. The new first day of the year was called "Lesser Nowruz." Later, King Hormizd I made the days between these two Nowruz celebrations into festivals too.

The Muslim Conquest and Calendar Changes

When Muslim rulers took over Persia in the mid-600s, they used the Islamic calendar. This calendar is based on the moon. Its year is shorter than a solar year. This caused problems, especially for taxes. A tax that used to be paid after harvest now had to be paid before it. It is said that the Caliph Omar brought back the Persian calendar for tax collection.

Around AD 895, the start of the tax year was adjusted again. By AD 1006, the spring equinox was once more lining up with Nowruz. So, the five extra days were moved back to their old place at the end of the last month.

The Jalali Calendar in the Medieval Era

In AD 1079, the Islamic calendar was replaced in Persia. This happened by order of King Jalal Al-Din Shah Seljuqi. The new calendar was created by Omar Khayyam and his team. It was named the Jalali Calendar. Khayyam and his team worked for eight years in Isfahan, the capital at the time. King Jalal Al-Din Shah paid for their work.

Khayyam designed his calendar so that the new year, seasons, and months would always start correctly. He made the first day of spring, Nowruz, a fixed day. Before his calendar, Nowruz could fall at different times in late winter or early spring.

The Jalali calendar was very accurate. It was based on careful astronomical calculations. This meant it did not need the extra "epagomenal" days. The months began when the sun entered a new sign of the zodiac.

About 120 years after the AD 1006 reform, Zoroastrians in India (Parsees) made their calendar align with Nowruz again. They added a second last month. Some Parsees later adopted a calendar where the first day of the year was always March 21. This calendar added a sixth extra day every four years. In 1911, the Jalali calendar became the official calendar of Persia.

The Modern Solar Hijri Calendar

The current Iranian calendar is called the Solar Hijri calendar. It was officially adopted on March 31, 1925. This happened during the early Pahlavi dynasty. The law stated that the first day of the year must be the first day of spring. This is based on the "true solar year."

The law also set the number of days in each month. The first six months have 31 days. The next five months have 30 days. The twelfth month has 29 days, but 30 days in a leap year. The calendar brought back the ancient Persian month names. These names are still used today. The first day, Farvardin 1, is the day whose midnight is closest to the exact moment of the spring equinox.

The calendar's starting point is the Hijrah of Muhammad. This was his journey from Mecca to Medina in AD 622. The law also stopped the use of the 12-year Chinese-Uighur calendar cycles. These cycles were commonly used but not officially approved.

On March 10, 1976, Shah Mohammad Reza Pahlavi introduced the "Imperial calendar." This calendar started counting years from 559 BC. This was the beginning of Cyrus the Great's rule and the start of the Achaemenian Empire. So, the year changed overnight from 1355 to 2535. However, this change was reversed just over two years later. On September 2, 1978, the calendar went back to the Solar Hijri system. This happened because of public unrest before the Iranian revolution.

Here's how the Solar Hijri calendar matches up with the Gregorian calendar:

See also

• Solar Hijri calendar
• Tabarian calendar
• Armenian calendar
• Lunar Hijri calendar
• Assyrian calendar
• Mandaean calendar
• Hebrew calendar
• Babylonian calendar
• Anno Graecorum
• Rumi calendar
• Royal stars