When and how was it decided that a week should have seven days?

Answer 1

The first pages of the Bible explain how God created the world in six days and rested on the seventh. This seventh day became the Jewish day of rest, the sabbath, Saturday.Calendar changes and reform have never interrupted the 7-day cycles. It very likely that the week cycles have run uninterrupted at least since the days of Moses (c. 1400 B.C.E.), possibly even longer.

According to those ancient Egyptians,the planet that ruled the first hour also governed the entire twenty-four hour period, and gave its name to that day.They believed that the first day was ruled by and named after Saturn (Saturday) and the second was ruled by (and named after) the Sun (Sunday).

Egyptians once divided all twelve 30-day months (of their 360-day calendar year) into three 10-day weeks in the same manner as Greeks of the same period. 6 The epoch at which planet worship caused them to change its length to seven days is not known, but it must have been over twenty-five hundred years ago because Herodotus, writing in his History during the 5th century B.C. said: "Here are some other discoveries of the Egyptians. They find...each day belongs to a god..."Egyptians then listed seven days in a wekk named after solar system members. It is interesting to note that these exact same solar system objects, and in the same sequence, were also used to name days in ancient India, Tibet and Burma.

Roman soldiers stationed in Egypt became accustomed to the pagan seven-day week and began to introduce it into their own homeland to replace their eight-day marketing week. Octavian (Caesar Augustus) and succeeding Roman rulers permitted this practice but it wasn't made official until the emperor Constantine took that step in A.D. 321.

The seven day week is known to have been unbroken for almost two millennia via the Alexandrian, Julian, and Gregorian calendars. The date of Easter Sunday can be traced back through numerous computistic tables to an Ethiopic copy of an early Alexandrian table beginning with the Easter of 311 as described by Otto Neugebauer in Ethiopic astronomy and computus. Only one Roman date with an associated day of the week exists from the first century and it agrees with the modern sequence, if properly interpreted. Jewish dates with a day of the week do not occur this early.

The week as we know was introduced around the 1st century. It gradually replaced the 8-day nundinal cycle previously in use, and became fully integrated into the calendar by order of Constantine I in AD 321. The order of the days was explained by Vettius Valens and Dio Cassius. According to these authors, it was a principle of astrology that the heavenly bodies presided, in succession, over the hours of the day. The Ptolemaic system asserts that the order of the heavenly bodies, from the farthest to the closest to the Earth, is: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon.

The seven-day week was established as imperial calendar in the late Roman empire and furthered by the Christian church for historical reasons. The British Empire used the seven-day week and spread it worldwide.

One viable theory correlates the seven day week to the seven (astrological) "planets" known to the ancients: Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. The number seven does not seem an obvious choice to match lunar or solar periods, however. A solar year could be more evenly divided into weeks of 5 days, and the moon phases five-day and six-day weeks make a better short term fit (6 times 5 is 30) to the lunar (synodic) month (of about 29.53 days) than the current week (4 times 7 is 28). The seven-day week may have been chosen because its length approximates one moon phase (one quarter = 29.53 / 4 = 7.3825).

Most Latin-based languages connect each day of the week with one of the seven "planets" of the ancient times: Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn.English has retained the original planets in the names for Saturday, Sunday, and Monday. For the four other days, however, the names of Anglo-Saxon or Nordic gods have replaced the Roman gods that gave name to the planets. Thus, Tuesday is named after Tiw, Wednesday is named after Woden, Thursday is named after Thor, and Friday is named after Freya.♥

Answer 2

The seven-day week became established in both the West and East according to different paths:


Babylonian, Hindu, and Jewish seven-day week:

Hindu civilization is known to have had the concept of seven-day week with instances in the Ramayana, a sacred epic written in Sanskrit about 300 BC, in which there is a mention of Bhanu-vaar meaning Sunday, Soma-vaar meaning Moon-day and so forth.
The ancient Babylonians are known to have observed a seven-day week; each day dedicated to a different deity. The significance of seven comes from Babylonian astronomy. There are the seven heavenly bodies or luminaries normally visible to the naked eye (the Sun, Moon, and 5 visible planets), and they associated each with a deity.
Other theories speculate that the fixed seven-day period is a simplification of a quarter of a lunar month.
The Hebrew and therefore Christian 7 day week corresponds to the creation of earth in 6 days and the seventh being a day of rest.

The Chinese use of the seven day week (and thus Korean, Japanese, Tibetan, and Vietnamese use) traces back to the 600's AD, when the concept of the seven "luminaries" of Babylonia spread to China. The days were assigned to each of the luminaries, but the week did not affect social life or the official calendar.

Various groups of citizens of the Roman Empire adopted the week, especially those who had spent time in the eastern parts of the empire, such as Egypt, where the 7-day week was in use. Contemporaneously, Christians, following the biblical instruction, spread the week's use along with their religion.

As the early Christians evolved from being Jewish to being a distinct group, various groups evolved from celebrating both the Jewish Sabbath (Saturday) and the first day or the Lord's Day (Sunday), to celebrating only Sunday.

Answer 3

Humans decided, but the Emperor of Rome had the last word, until the English came along. They settled the argument with big Ben. And then a bunch of Sophists invented the Big Bang.
So the question should be, what time is it according to the Big
Bang? I have a feeling that is not the last word on the issue.

Answer 4

It comes from the Bible. God created the international in six days and rested on the seventh. In different words, it somewhat is an historic custom started by way of the Israelites, and unfold international by way of Christians and Muslims, who additionally based their faith and calendar on the Bible. The Roman calendar did no longer divide the month into weeks.

Answer 5

The bible, Genesis chapter 1