Calendar
The Mesopotamian calendar was primarily lunar, and the months began with the first sighting of the young, waxing crescent moon just after sunset on the western horizon. As a result, each month was either 29 or 30 days long, and the year approximately 354 days. Ritual celebrations, however, were aligned with the seasons, and thus solar in nature. Therefore, intercalary months were added when necessary to keep the lunar calendar in agreement with the seasonal schedule.
The Mesopotamian calendar was primarily lunar, and the months began with the first sighting of the young, waxing crescent moon just after sunset on the western horizon. As a result, each month was either 29 or 30 days long, and the year approximately 354 days. Ritual celebrations, however, were aligned with the seasons, and thus solar in nature. Therefore, intercalary months were added when necessary to keep the lunar calendar in agreement with the seasonal schedule.