 The earliest classical calendrical poem which might have inspired Ovid is the "Works and Days" of Hesiod, which includes mythological lore, astronomical observations, and an agricultural calendar.For the astronomical sections, Ovid was preceded by Aratus' "Phaenomena" as well as lost poetry on constellations and probably Germanicus' adaptation of Aratus ("Fasti" 1.17–27).The most significant influence on Ovid were the Roman "fasti", the Roman calendrical lists, which included dates, notices of festivals, ritual prohibitions and proscriptions, anniversaries of important events, and sometimes aetiological material.