Pentecontad Calendar - Overview

Overview

In Akkadian, the pentecontad calendar was known as hamšâtum and the period of fifteen days at the end of the year was known to Babylonians as shappatum. The religious injunction to "observe the Sabbath" is thought to derive from the injunction to observe the shappatum, the period of harvest time at the end of each year in the pentecontad calendar system.

Each fifty day period was made up of seven weeks of seven days and seven Sabbaths, with an extra fiftieth day, known as the atzeret.

Used extensively by the various Canaanite tribes of Palestine, the calendar was also thought to have been used by the Israelites until the official adoption of a new type of solar calendar system by King Solomon.

The liturgical calendar of the Essenes at Qumran was a pentecontad calendar, marked by festivals on the last day of each fifty day period such as the Feast of New Wine, the Feast of Oil, and the Feast of New Wheat, etc.

Philo expressly connected the "unequalled virtues" of the pentecontad calendar with the Pythagorean theorem, further describing the number fifty as the "perfect expression of the right-angled triangle, the supreme principle of production in the world, and the 'holiest' of numbers."

Tawfiq Canaan (1882 - 1964) described the use of such a calendar among Palestinians in southern Palestine, as did his contemporary Gustaf Dalman who wrote of the practices of Muslim agriculturalists who used Christian designations for the fiftieth day, "which in turn overlaid far more ancient agricultural practices: grape-watching, grape-pressing, sowing, etc."

Julius Morgenstern argued that the calendar of the Jubilees has ancient origins as a somewhat modified survival of the pentecontad calendar.