In Mesopotamia the sun year become divided into seasons, the “summer time,” which blanketed the barley harvest inside the 2d half of might also or inside the beginning of June, and the “iciness,” which roughly corresponded to today’s fall–wintry weather. 3 seasons (Assyria) and 4 seasons (Anatolia) have been counted in northerly international locations, however in Mesopotamia the bipartition of the yr appeared herbal.
As overdue as about 1800 BCE the prognoses for the welfare of the city of Mari, at the center Euphrates, have been taken for 6 months. The months started out at the primary visibility of the new Moon, and in the 8th century BCE court astronomers still said this essential remark to the Assyrian kings. 
The names of the months differed from town to metropolis, and in the same Sumerian town of Babylonia a month could have several names, derived from fairs, from tasks (e.g., sheepshearing) usually carried out within the given month, and so forth, consistent with nearby desires. on the other hand, as early as the 27th century BCE, the Sumerians had used synthetic time devices in referring to the tenure of some high reliable—e.g., on N-day of the flip of office of PN, governor.12 = 360 days.
The Sumerian administration additionally wanted a time unit comprising the whole agricultural cycle; as an example, from the shipping of latest barley and the settling of pertinent money owed to the subsequent crop. This financial 12 months began about two months after barley reducing.
For different purposes, a year started out before or with the harvest. This fluctuating and discontinuous yr became no longer unique sufficient for the meticulousaccounting of Sumerian scribes, who by way of 2400 BCE already used the schematic 12 months of 30 × 12 = 360 days.At approximately the equal time, the idea of a royal 12 months took specific form, beginning possibly on the time of barley harvest, while the king celebrated the brand new (agricultural) yr by using offering first culmination to gods in expectation of their benefits for the yr.
whilst, within the path of this year, a few royal take advantage of (conquest, temple building, and so on) verified that the fates had been fixed favourably via the celestial powers, the year become named as a consequence; for example, because the 12 months wherein “the temple of Ningirsu became constructed.” till the naming, a year become described as that “following the yr named (after such and such event).” the use of the date formulas was supplanted in Babylonia by using the counting of regnal years inside the 17th century BCE.
World Templats 