28 Dec The most accurate calendar in the world (Part 1)
The Persian calendar: a Masterpieces in astronomy in the period of more than 1000 years ago
Iranian astronomy calendar is the most accurate and the most complete calendar around the world. This calendar was written according to the Earth’s movement around the sun. For example, in comparing it with the ad calendar, second one has only one false day per 3320 years, but Iranian calendar has just two false days per 10,000 years!
For this reason many mathematicians and astronomers believe that Iranian calendar is the most complete and creative calendar in the world. The emergence of this calendar has an interesting story that I think that can be useful for reading.
The reasons for the emergence of the Iranian calendar Iranian ancient people emerged their first calendar 7000 years ago. In this calendar March 21 was the first day of the year and this day was the first day of spring season. Nobody knows who exactly emerged this calendar! But Iranian calendar has been changed several times and finally this was converted to a more accurate calendar. This calendar is the most famous solar calendar in Iran.
In 1006 there was a king in Iran. The name of this king was Jalalodole Malek Shah Saljooghi. That period of his authority was 400 years after Arabs invasion to Iran and before that, Iranian people didn’t have ancient religions (1). They were Muslim and they had to use Arabic calendar (2). This problem caused destroying many sources of calculating the Iranian calendar. So calculation of the first day of the year in Iran, had some mistakes.
Jalalodole Malek Shah Saljooghi ordered and wanted Iranian calendar recomputed and re-written. Because Iranian people had problems in calculating important holidays in Iran such as Nowruz and Yalda. (4) For this purpose, many math mathematicians and astronomers had been invited by the king. In between all of them, Omar Khayyam (3) was the best and brightest person. Because Khayyam was a poet, philosopher, mathematician and astronomy and he was skilled in various fields of science.
The first time Iranian calendar called Jalali was because this calendar was written by the order of Jalalodole Malek Shah Saljooghi. Without a doubt, Iranian calendar is the best calendar that is been written. This calendar was written by many researches and observations in Isfahan and Neyshaboor observatory. They were important cities in Iran that time.
After Mongolian invasion to Iran which happened 200 years after Jalalodole Malek Shah Saljooghi, Jalali calendar was not used less and more as people used Arabic calendar. But in 1925 Iranian Parliament approved Jalali calendar for home calendar in Iran. That year this calendar called solar calendar. Iranian people call this calendar solar, and Arabic people call it: Jalali. And another countries call that: Iranian calendar.
By Narges Kharghani
1-Iranian people was Zoroastrians before Arab invasion to Iran. Several Historical evidences show that more than 90 percent of Iran’s population was Zoroastrian 1400 years ago. This religion belonged to the Old Iranian prophet Zoroaster. He was born in Iran 3000 years ago. At this moment, few Zoroastrians live in Iran and India.
2-Arabic calendar or lunar calendar is been used in Arabic countries. This calendar has been calculated according to the movement of the moon around the earth. For this reason often this calendar is 10 days less than solar calendar and ad calendar. Arabic calendar has just 355 days in a year!
3-Omar Khayyam is Iranian poet, philosopher, mathematician and astronomy. He had contributions with different sciences. He was the first person that had proved the existence of the third degree equation which may there are more than one answer or there may be some extra questions. Khayyam did many works in algebra that is been using till now. Theories of materialism in philosophy were very controversial in 1000 years ago. Khayyam stated his philosophy theories in his poems. There are many paradoxical opinions about Khayyam’s poems yet. Western nations recognized that philosophy of Khayyam for the first time had been translated by Edward FitzGerald’s on Omar Khayyam’s poems. Edward FitzGerald was an English writer in 19 century. For a while, he lived in India and he read Khayyam’s poems and he loved Khayyam’s philosophy. In the western countries Khayyam is mostly well- known for his poems and philosophy methods, but other aspects of his talents never had been mentioned from them.
4- Yalda is the longest night of the year in Persian culture and this night is very important in Iranian domestic ceremonies. It’s been held every year in December 21. In this night, Iranian people have parties and family members gather together and they will sing some spiritual poems and eat fruits such as watermelon and pomegranate with nuts and other stuffs. and they don’t fall asleep until dawn.