Ancient Egyptian Calendar
古埃及的历法包括太阴历和准太阴历等,大体上将每年分为 3 个季节:泛滥季、长出五谷季、收割季。同时以 365 天为 1 年,1 年 12 个月,每月 30 天,年终另外再加 5 天作为节日。比现行的阳历只少 1/4 天。古罗马的儒略历就是在此基础上修订的。
The ancient Egyptian calendar was inventedover 5000 years ago. It was originally based on the lunar cycle of 12 months,which the Egyptians grouped into three seasons of four months each to coincidewith the rise and fall of the waters of the Nile. However, although theflooding of the Nile began each year around the end of June, the floodsoccurred within a range of 80 days and were not accurate enough to base acalendar on. So the ancient Egyptians, having noticed that the Nile’s risingcoincided with the heliacal rising of the star Sirius, the brightest star inthe sky, based the year on the cycle of its reappearance.
The beginning of the year, also called"the opening of the year", was determined by the appearance of thestar Sirius, in the constellation of Canis Major, which occurred around June21st. However, because the rising of Sirius is a stellar event, which means itoccurs every 365 14 days, the rising of the star did not precisely match thecalendar, which was based on the lunar cycle and so had an average of 354days--11 days less than a solar year. This meant that the rising of the starwould very quickly be out of sync with the calendar. To correct this, theEgyptians introduced an extra month to create a “Great Year” of 384 days every2 or 3 years.
However, because this calendar was eithernot accurate enough, too complicated, or unsuitable for economic andadministrative purposes, a standard calendar was introduced in the Old Kingdomto run along side the lunar calendar. This calendar, which probably resultedfrom counting the number of days between successive risings of Sirius.
The new “Civic” calendar year was dividedinto 3 seasons, each with four months. Each of the 12 months had 30 daysdivided into 3 decades (weeks) of 10 days each for a total of 360 days. Theseasons of the Egyptian calendar were believed to have been chosen tocorrespond to the cycles of the Nile which was central to the life of theEgyptians. Because they lived an agrarian lifestyle the seasons were namedafter the significant events for farming. Translated to our Gregorian calendar,the dates of these seasons seem to vary considerably as do the names of boththe seasons and the months. For example, the season of Akhet, is considered byone reference to occur between August 29th and December 26th, whereas anotherreferences place it between June 21st and October 21st .
1. 古埃及历法在大约 5000 年前被发明。它基于月运周期的 12 个月份。
4. 新的 civic 日历和尼罗河的周期吻合。
heliacal rising 偕日出