星期制是如何起源的？

01-30

為什麼一個星期有七天？

源自古巴比倫，他們把1個月分為4周，每周有7天，即1個星期。7是五大行星和日月之和。到了羅馬帝國時期，星期製成為了「國際標準」。

正如@free_POC所說，《聖經》的成書是很晚的，猶太人的文明也很「年輕」，《聖經》里的傳說很多都可以在古埃及等更老的文明裡找到源頭。

中國古代叫「七曜」，與天上星星對應，至少在漢朝就有了，但究竟是自我產生還是外部傳入的，還很有爭議。日本等國是直接從中國引進，所以至今都叫「日曜日、月曜日、火曜日……」

西方的「星期」，最早產生於蘇美爾文明（美索不達米亞的最早文明，距今至少4000年前，也是目前教科書上一般公認的已知最早文明），然後被其後的古巴比倫文明延續，被古猶太教吸收，因此後面產生的基督教、伊斯蘭教都繼承了這種表示方式……

應該是巴比倫人，《聖經》在成書的時間上太后了。

星期在中國古稱「七曜」。七曜在中國夏商周時期，是指日、月、及五大行星等七個主要星體，是當時天文星象的重要組織成份。

後來借用作七天為一周的時間單位，故稱星期。在西方，古巴比倫人首先使用七天為一周的時間單位，後來猶太人把它傳到古埃及，又由古埃及傳到羅馬，公元3世紀以後，就廣泛地傳播到歐洲各國。明朝末年在歐洲和中國的交流中傳入了中國，到了民國以後被廣泛採用。

來源：http://zh.wikipedia.org/wiki/%E6%98%9F%E6%9C%9F

巴比倫人。他們不但規定了一周七天，還規定了一天24小時，一小時60分鐘。甚至圓形分360度等等。

至於他們怎麼發現的，抱歉不能給閣下提供更詳細的信息啦

《聖經》

星期又作周或者禮拜，是一個時間單位，每星期有7日。

中國古代有七曜此詞，首現於東晉范寧的《春秋穀梁傳序》：「陰陽為之愆度，七曜為之盈縮。」楊士勛疏：「謂之七曜者，日月五星皆照天下，故謂之曜。」五星指火、水、木、金、土。不過唐朝以前還未有使用七星指代輪迴的7日。古巴比倫人首先使用7日為一周的時間單位，後來猶太人把它傳到古埃及，又由古埃及傳到羅馬，公元3世紀以後，就廣泛地傳播到歐洲各國。明朝末年，在歐洲和中國的交流中再傳入了中國，到了民國以後被廣泛採用。

起源也分東西方兩個方面：

東亞中國的「七曜」和西方以七星命名的七天相對應，大約發生於唐朝。

西方西方語言中星期的表達法大多源於拉丁語。而拉丁語的情況可分為基督教崛起前和崛起後兩種；

更多詳細內容可以到維基百科，查「星期」：星期

還有：星期中的日子這裡是全世界各國星期幾的叫法。

『a little history of the world ，貢布里希,其中第四章"sunday,monday..."，算是講清楚了這個問題吧，附部分原文

For both the Babylonians and the Assyrians worshipped the sun
and the moon, and also the stars. On clear, warm nights, through-
out the year and over centuries, they observed and recorded every-
thing they saw in the skies. And because they were intelligent, they
noticed that the stars revolved in a regular way. They soon learnt to
recognise those that seemed fixed to the vault of heaven, reappear-
ing each night in the same place. And they saw shapes in the con-
stellations and gave them names, just as we do when we speak of
the Great Bear. But the stars which seemed to move over the vault
of heaven, now, say, towards the Great Bear, and now towards the
Scales, were the ones that interested them most. In those days
people thought that the earth was a flat disk, and that the sky was
a sort of hollow sphere cupped over the earth, that turned over it
once each day. So it must have seemed miraculous to them that,
although most of the stars stayed fixed to the heavens, some
seemed, as it were, only loosely fastened, and able to move about.

Today we know that these are the stars that are close to us,
and that they turn with the earth around the sun. They are called
planets. But the ancient Babylonians and Assyrians couldn』t know
that, and so they thought some strange magic must lie behind it.
They gave a name to each wandering star and observed them con-
stantly, convinced that they were powerful beings whose positions
influenced the destinies of men, and that by studying them they
would be able to predict the future. This belief in the stars has a
Greek name: astrology.

Some planets were believed to bring good luck, others misfortune: Mars meant war and Venus, love. To each of the five planets
known to them they dedicated a day, and with the sun and the
moon, that made seven. This was the origin of our seven-day week.
In English we still say Satur (Saturn)-day, Sun-day and Mon
(moon)-day, but the other days are named after different gods. In
other languages – such as French or Italian – most of the days of
the week still belong to the planets that the Babylonians first
named. Would you ever have guessed that our weekdays had such a strange and venerable history, reaching back all those thousands
of years?

應該是寫《聖經》的那個人或許跟7有著莫大的淵源，因此《聖經》里才會被寫到上帝和星期制的故事。