Mesopotamia 12 Month Calendar. Months in mesopotamia and stages in the agricultural calendar for the city of girsu: However, to align the calendar with the solar year, which is approximately 365 days,.
The origin of the babylonian calendar can be traced back to the ancient mesopotamian civilization, specifically to the sumerians who were the earliest known inhabitants of the. The babylonian calendar was a lunisolar calendar with years consisting of 12 lunar months, each beginning when a new crescent moon was first sighted low on the western.