The Jalali calendar, a sidereal calendar used…

The Jalali calendar, a sidereal calendar used in Persia, is reformed in 1075 under instructions from Nizam al-Mulk Throughout Malik's reign, new institutions of learning will be systematically established throughout the Seljuq lands, in such cities as Herat, Baghdad, Mosul, Basra, Nishapur, and Isfahan, the famous Nizamiyyah schools, which are named after him.

In many respects, these schools will turn out to be the predecessors and models of universities that will be established in Europe.