[1] In some other languages, the days are named after corresponding deities of the regional culture, beginning either with Sunday or with Monday.
The seven-day week was adopted in early Christianity from the Hebrew calendar, and gradually replaced the Roman internundinum.
The Babylonians invented the actual[clarification needed] seven-day week in 600 BCE, with Emperor Constantine making the Day of the Sun (dies Solis, "Sunday") a legal holiday centuries later.
The earliest evidence for this new system is a Pompeiian graffito referring to 6 February (ante diem viii idus Februarias) of the year 60 CE as dies solis ("Sunday").
[citation needed] The Ptolemaic system of planetary spheres asserts that the order of the heavenly bodies from the farthest to the closest to the Earth is Saturn, Jupiter, Mars, Sun, Venus, Mercury, and the Moon; objectively, the planets are ordered from slowest to fastest moving as they appear in the night sky.
[5] The days were named after the classical planets of Hellenistic astrology, in the order: Sun (Helios), Moon (Selene), Mars (Ares), Mercury (Hermes), Jupiter (Zeus), Venus (Aphrodite), and Saturn (Cronus).
[citation needed] or ਸ਼ਨੀਵਾਰShanīvār or ਸਨਿੱਚਰਵਾਰSaniccharvār or ਸਨੀਵਾਰSanīvār Shukkarvār شکروار Chanicchar چھنچھر or Chaniccharvār چھنچھروار The Southeast Asian tradition also uses the Hindu names of the days of the week.
The Chinese had apparently adopted the seven-day week from the Hellenistic system by the 4th century AD, although by which route is not entirely clear.
It was again transmitted to China in the 8th century AD by Manichaeans, via the country of Kang (a Central Asian polity near Samarkand).
[24] The 4th-century AD date, according to the Cihai encyclopedia,[year needed] is due to a reference to Fan Ning (范寧), an astrologer of the Jin dynasty.
In Japan, the seven-day system was kept in use (for astrological purposes) until its promotion to a full-fledged (Western-style) calendrical basis during the Meiji era.
The Slavic, Baltic and Uralic languages (except Finnish and partially Estonian and Võro) adopted numbering but took Monday rather than Sunday as the "first day".
[26] In Slavic languages, some of the names correspond to numerals after Sunday: compare Russian vtornik (вторник) "Tuesday" and vtoroj (второй) "the second", chetverg (четверг) "Thursday" and chetvjortyj (четвёртый) "the fourth", pyatnitsa (пятница) "Friday" and pyatyj (пятый) "the fifth"; see also the Notes.
The modern Chinese names for the days of the week are based on a simple numerical sequence.
[28] A slightly informal and colloquial variant to 日 is 天 (tiān) "day", "sky" or "heaven".
While all varieties of Mandarin may pronounce 星期 as xīngqi and 禮拜/礼拜 as lǐbai, the second syllable with the neutral tone, this is not reflected in the table either for legibility.
Saint Martin of Dumio (c. 520–580), archbishop of Braga, decided not to call days by pagan gods and to use ecclesiastic terminology to designate them.
☽1 After No Work ☽2 After Bazaar ☽3 Head of Week ☽4 Master (as in Pir, because Muhammad was born on a Monday) ☽5 From an Old Burmese word, not of Indic origin.