The Old Imperial Era (formerly known as the Imperial Year) is the standard calendar system of the Northern Kingdoms. It was insituted when Stanislaus of Octobirit was crowned Emperor of Calligia. The calendar system remained in use through out all the lands which the Octovian Dynasty ruled over, even after the old Empire was deposed by the Antagia Rebellion.

Sabres of Infinity begins in OIE 602.