Institutions of learning in the south were also renowned, including the Zongmingguan (Imperial Nanjing University), where the famed Zu Chongzhi (mentioned above) had studied. Zu Chongzhi devised the new Daming Calendar in 465, calculated one year as 365.24281481 days (which is very close to 365.24219878 days as we know today), and calculated the number of overlaps between sun and moon as 27.21223 (which is very close to 27.21222 as we know today). Using this number he successfully predicted 4 eclipses during a period of 23 years (from 436 to 459).