Understanding the Persian Calendars: Jalali and Khorshidi

Understanding the Persian Calendars: Jalali and Khorshidi

The Persian calendar system has a rich history, with various forms evolving over time. Two notable calendars are the Jalali calendar and the Solar Hijri calendar, often referred to as the Khorshidi calendar in informal contexts. While the term "Lunar Persian Calendar" might be misleading, as the primary Persian calendars are solar, we'll explore the Jalali calendar and clarify the distinction between solar and lunar systems.

Jalali Calendar

The Jalali calendar, named after Sultan Jalaluddin Malik-Shah I, was introduced on March 15, 1079. It was developed by a team of astronomers led by Omar Khayyam during the Seljuk Empire. This solar calendar was designed to align with the solar year, ensuring that the new year, Nowruz, coincided with the vernal equinox. The Jalali calendar was based on precise solar transits through the zodiac, making it highly accurate but complex to compute.

Key Features of the Jalali Calendar:

• Solar Basis: Unlike the Islamic calendar, which is lunar, the Jalali calendar is solar, ensuring it stays aligned with the seasons.

• Zodiac Alignment: Months begin when the sun enters a new zodiac sign.

• No Leap Years: Originally, the calendar did not require leap years due to its precise astronomical calculations.

• Complexity: The need for continuous astronomical observations made it challenging to maintain over time.

Evolution to the Solar Hijri Calendar

In 1925, the Jalali calendar was simplified and modified to create the Solar Hijri calendar, which is currently …