It was discovered in Coligny, France, and is now on display in the Palais des Arts Gallo-Roman museum, Lyon.It dates from the end of the second century AD, when the Roman Empire imposed the use of the Julian Calendar in Roman Gaul.However, several of the objects depicted are Celtic, such as the helmets and the Celtic war trumpet (carnyx).
The Gundestrup Cauldron was probably made between 150 BC and the Birth of Christ.
The figures are boldly embossed and decorated with carefully punched patterns.
The Coligny Calendar is an attempt to reconcile the cycles of the moon and sun, as is the modern Gregorian calendar.
However, the Coligny calendar considers the phases of the moon to be important, and each month always begins with the same moon phase.
The calendar uses a mathematical arrangement to keep a normal 12-month calendar in sync with the moon and keeps the whole system in sync by adding an intercalary month every 2 years.