March 2020 calendars free download printables: Old Persian inscriptions and tablets indicate that early Iranians used a 360-day calendar based on the solar observation directly and modified for their beliefs. Days were not named. The months had two or three divisions depending on the phase of the moon. Twelve months of 30 days were named for festivals or activities of the pastoral year. A 13th month was added every six years to keep the calendar synchronized with the seasons.
The ancient Sumerian calendar 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 resulted in scribes and scholars referring to them as “the first month”, “the fifth month”, etc.To keep the lunar year of 354 days in step with the solar year of 242 days an extra month was added periodically, much like a Gregorian leap year. There were no weeks in the Sumerian calendar. Holy days and time off from work were usually celebrated on the first, seventh and fifteenth of each month. In addition to these holy days, there were also feast days which varied from city to city.