The term calendars itself is taken from the calends, the term for the first day of the month in the Roman calendar, related to the verb calare "to call … 展开

Many Upper Paleolithic cave paintings of animals from across western and central Europe are accompanied by sequences of dots and lines. It has been hypothesized that these are 展开

Babylonia and Persia
Although the earliest evidence of Iranian calendrical traditions is from the second millennium BC, … 展开

Ethiopian Calendar
The Ge'ez or Ethiopian Calendar is a calendar originating from the Ethiopian Empire. It is the liturgical year for Ethiopian and 展开

The ancient Sumerian calendar, roughly dated to 2,100 BC, divided a year into 12 lunar months of 29 or 30 days. Each month began with the sighting of a new moon. Sumerian months had no uniform name throughout Sumer because of the religious diversity. This … 展开

Christian Europe
The oldest calendar of saints of the Church of Rome was compiled in the mid-4th century, under Pope Julius I or Pope Liberius. It contained both pagan and Christian festivals. The oldest extant manuscript of the early … 展开

Of all the ancient calendar systems, the Maya and other Mesoamerican systems are the most complex. The Mayan calendar had two years, the 260-day Sacred Round, or tzolkin, and the 365-day Vague Year, or haab.
The Sacred Round of … 展开