The Ancient Macedonian calendar is a lunisolar calendar that was in use in ancient Macedon in the 1st millennium BCE. It consisted of 12 synodic lunar months (i.e. 354 days per year), which needed intercalary months to stay in step with the seasons. By the time the calendar was being used across the Hellenistic world, seven total embolimoi (intercalary months) were being added in each 19 year Metonic cycle. The names of the ancient Macedonian Calendar remained in use in Syria even into the Christian era.