Calendar question over star disc

BBC: Archaeologists have revived the debate over whether a spectacular Bronze Age disc from Germany is one of the earliest known calendars. The Nebra disc is emblazoned with symbols of the Sun, Moon and stars and said by some to be 3,600 years old. Writing in the journal Antiquity, a team casts doubt on the idea the disc was used by ancient astronomers as a precision tool for observing the sky. They instead argue that the disc was used for shamanistic rituals.