In 1079 CE during the Seljuq dynasty era, a group of eight scholars led by astronomer and polymath Omar Khayyam calculated and established the Jalali calendar, computing the year starting from Nowruz.Before the collapse of the Soviet Union, Iran and Afghanistan were the only countries that officially observed the ceremonies of Nowruz. When the Caucasian and Central Asian countries gained independence from the Soviets, they also declared Nowruz as a national holiday.Nowruz was added to the UNESCO List of the Intangible Cultural Heritage of Humanity in 2010.