TEHRAN – Iranians have marked the National Khayyam Commemoration Day, paying tribute to the legendary polymath.
Ghiyāth al-Dīn Abū al-Fatḥ ʿUmar ibn Ibrāhīm Nīsābūrī (May 18, 1048 – December 4, 1131), commonly known as Omar Khayyam was a Persian mathematician, astronomer, historian, philosopher, and poet, who was born in the Iranian city of Nishapur.
The young Omar was an avid student and quickly became skilled in mathematics, astronomy, and philosophy.
As a scholar, he was contemporary with the rule of the Seljuk dynasty in Iran.
As an astronomer, he designed the Jalali calendar, a solar calendar with a very precise 33-year intercalation cycle  that provided the basis for the Persian calendar that is still in use after nearly a millennium. 
Khayyam announced in 1079 that the length of the year was measured as 365.24219858156 days. Given that the length of the year is changing in the sixth decimal place over a person’s lifetime, this is outstandingly accurate. For comparison the length of the year at the end of the 19th century was 365.242196 days, while today it is 365.242190 days.
He spent most of his life in Persian intellectual centers such as Samarkand and Bukhara and enjoyed the favor of the Seljuk sultans who ruled the region.
Khayyam wrote several works including Problems of Arithmetic, a book on music, and one on algebra before he was 25 years old.
In 1070 he moved to Samarkand in Uzbekistan, which is one of the oldest cities in Central Asia. There, Khayyam was supported by Abu Tahir, a prominent jurist of Samarkand, and this allowed him to write his most famous algebra work, Treatise on Demonstration of Problems of Algebra.
As a mathematician, Khayyam discovered that a cubic equation can have more than one solution. He demonstrated the existence of equations having two solutions but does not appear to have found that a cubic can have three solutions.
Outside the world of mathematics, Khayyam is best known for nearly 600 short four-line poems in the Rubaiyat.
Interestingly, Khayyam’s poetry was not published in the Muslim world until 200 years after his demise.
“The Moving Finger”, translated by English poet Edward Fitzgerald, is one of the most popular quatrains. It reads:
The Moving Finger writes; and having writ,
 Moves on: nor all your Piety nor Wit
 Shall lure it back to cancel half a Line,
 Nor all your Tears wash out a Word of it.