Luigi Lilio

…the Neapolitan astronomer and physician Luigi Lilio Ghiraldi (died 1576) and the German Jesuit and mathematician Christopher Clavius, Gregory corrected the errors of the Julian calendar created by Julius Caesar in 46 bce. The new Gregorian calendar, introduced on February 24, 1582, in the bull Inter gravissimas (“In the Gravest…

…by the astronomer and physician Luigi Lilio (also known as Aloysius Lilius; died 1576).