Is the solar hijri calendar the most accurate among the calendars?

Muhammad Rehmanpour-Iran

The Iranians celebrate annually with the advent of the spring semester of Nowruz and New Year, according to the solar Hijri calendar, which is the most ancient and accurate calendar in the world, as the migration of the Prophet Muhammad, may God bless him and grant him peace from Mecca to Medina, took his principle, relying on the Earth’s rotation around the sun .

Beginning with the birth and birth of Islam, the Iranians followed the Ostaei calendar, which is a solar calendar emanating from (Zoroastrian religion), up to Islam and following the lunar Hijri calendar. In the year 471 AH, Iran followed the solar calendar again during the Seljuk period.

Celestial calendar
The Sultan of the Seljuks ordered the Jalal al-Dawla Malik Shah, Ghiath al-Din Omar bin Ibrahim Khayyam al-Nisaburi and some scholars at the Isfahan Observatory, to follow the new calendar for the inaccuracy of the lunar Hijri calendar from the administrative point of view. The scholars established the new solar calendar, or as it is called the Jalali calendar, according to King Jalal al-Dawla Malik Shah.

As for the solar hijri calendar currently approved, it is the same Jalali calendar, but with a change in the principle of calendar from the year of the coronation of the Seljuk king Jalal al-Dawla, to the principle of the migration of the Prophet Muhammad, peace be upon him. The principle of evaluation was changed by Abd al-Ghaffar Najm al-Dawla, professor of the Dar al-Funun during the reign of Nasir al-Din Shah al-Qajari nearly 135 years ago.

Amir Hassanzadeh, a specialist at the Center for Calendar and Geophysics at Tehran University, said in his interview with Al-Jazeera Net that the solar year begins with a spring equinox with the first beginning of the Aries (Forwardin in Persian) and the average length of the solar Hijri year is 365 days, 5 hours, 48 ​​minutes, and 97.45 seconds.

Leap years
Hassan Zadeh said that he adds a day to the year every four years and is known as the leap year (due to 5 hours and 48 additional minutes per year) and the leap year is calculated sometimes after 5 years (because the additional hours are not completed to 6 hours, i.e. quarter of a day), which increases the accuracy of the solar Hijri calendar Compared to any other calendar. For example, there is a one-day error in the Gregorian calendar that occurs every 3300 years, which does not happen in the solar Hijri calendar.

The names of angels
He also pointed out that the naming of the most famous solar hijri calendar in Iran depends on the names of the Zoroastrian god and angels such as Forwardin, Ardebehesht and Khordad. Whereas, in naming the most famous in Afghanistan, he relied on constellations such as Aries, Taurus, Gemini and Pisces.

The solar hijri calendar was officially adopted in Iran and Afghanistan, and it is considered the second calendar in Tajikistan and among the Kurds. Saudi Arabia also uses it to pay the salaries of its employees.

The number of days in the first six months of the solar Hijri calendar is 31 days, while the number of days in the second half of the year is 30 days, except for the last month. It is originally 29 days in regular years and 30 days in leap years.

The Hijri solar year is also 10 lunar Hijri years longer, or approximately 11 days each year, where every 100 Hijri solar years equal 103 lunar Hijri years.

Accuracy of the calendar
Ali Akbar Nairi, a specialist at the Center for Calendar and Geophysics at the University of Tehran, believes that the accuracy of the solar Hijri calendar is due to matching the moment of the New Year’s transition each year with the first day of spring, so it is considered one of the most accurate calendars in the world.

For example, on the Islamic Hijri New Year, the New Year turns at the moment when the sun crosses its spring orbit in the New Year, and everyone around the world celebrates at the same hour, minute and second. But on New Year's Day, the New Year turns at 24:00 according to the hour of each country.

The Islamic Hijri New Year always begins with the first spring of each year, which indicates the beginning of life and a new birth.

Iranians celebrate Nowruz (meaning a new day) with the beginning of each year, and the new solar Hijri year begins this year at 7:19 minutes and 37 seconds on the morning of Friday, March 20, which is the year 1399 Hijri.