Det fanns eventuellt regelbundna årstider i antikens historia, ännu längre tillbaka än Heros ålder. Skrivning och skivor var sällsynta redan då och det mesta av vad vi vet från den tiden är legenden vidarebefordrade av historien.
Maestrarna har tittat på frågan men har inte kunnat avsluta något eftersom det inte finns tillräckligt med information från det för länge sedan ...
Though the Citadel has long sought to learn the manner by which it may predict the length and change of seasons, all efforts have been confounded. Septon Barth appeared to argue, in a fragmentary treatise, that the inconstancy of the seasons was a matter of magical art rather than trustworthy knowledge. Maester Nicol's The Measure of the Days—otherwise a laudable work containing much of use—seems influenced by this argument. Based upon his work on the movement of stars in the firmament, Nicol argues unconvincingly that the seasons might once have been of a regular length, determined solely by the way in which the globe faces the sun in its heavenly course. The notion behind it seems true enough—that the lengthening and shortening of days, if more regular, would have led to more regular seasons—but he could find no evidence that such was ever the case, beyond the most ancient of tales.
The World of Ice and Fire - Ancient History: The Long Night
Så att svara på din titelfråga: Årstiderna kan ha varit en normal längd på en gång men det är innan inspelad historia.