An Olympiad (, olympiás) is a period of four years associated with the Olympic Games of the Ancient Greeks. During the Hellenistic period, beginning with Ephorus, it was used as a calendar epoch. By this reckoning, the first Olympiad lasted from the summer of 776 BC to that of 772 BC. By extrapolation to the Gregorian calendar, the year of the th Olympiad begins in (Northern-Hemisphere) mid-summer 2016.