Greco-Roman tradition Between the first and third centuries CE, the
Roman Empire gradually replaced the eight-day Roman
nundinal cycle with the seven-day week. 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"). Another early witness is a reference to a lost treatise by
Plutarch, written in about 100 CE, which addressed the question of: "Why are the days named after the planets reckoned in a different order from the 'actual' order?" The treatise is lost, but the answer to the question is known; see
planetary hours. 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. 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). The seven-day week spread throughout the Roman Empire in late antiquity. By the fourth century CE, it was in wide use throughout the Empire. The Greek and Latin names are as follows:
Romance languages Except for in
Portuguese and
Mirandese, the Romance languages preserved the Latin names, except for the names of Sunday, which was replaced by
[dies] Dominicus (Dominica), that is, "the
Lord's Day", and of Saturday, which was named for the Jewish
Sabbath. Mirandese and Portuguese use numbered weekdays, but retain
sábado and
demingo/
domingo for weekends. Meanwhile,
Galician occasionally uses them alongside the traditional Latin-derived names, albeit to a lesser extent (see
below).
Celtic languages Early
Old Irish adopted the names from Latin, but introduced separate terms of Norse origin for Wednesday, Thursday and Friday, then later supplanted these with terms relating to church fasting practices. In Welsh, the word for ‘day’ is replaced by the words for ‘morning' , ’night’ or ‘afternoon’ , etc to say ‘Monday morning’ , or ‘Friday night’ , etc. It is never * or * which are ungrammatical.
Albanian language Albanian adopted the Latin terms for Tuesday, Wednesday and Saturday, translated the Latin terms for Sunday and Monday using the native names of
Diell and
Hënë, respectively, and replaced the Latin terms for Thursday and Friday with the equivalent native deity names
Enji and
Prende, respectively.
Adoptions from Romance Other languages adopted the week together with the Latin (Romance) names for the days of the week in the colonial period. Several constructed languages also adopted the Latin terminology. With the exception of
sabato, the Esperanto names are all from French, cf. French
dimanche, lundi, mardi, mercredi, jeudi, vendredi.
Germanic tradition The
Germanic peoples adapted the system introduced by the Romans by substituting the
Germanic deities for the Roman ones (with the exception of
Saturday) in a process known as . The date of the introduction of this system is not known exactly, but it must have happened later than 100 AD but before the introduction of Christianity during the 6th to 7th centuries, i.e., during the final phase or soon after the collapse of the
Western Roman Empire. This period is later than the
Common Germanic stage, but still during the phase of undifferentiated
West Germanic. The names of the days of the week in
North Germanic languages were not
calqued from Latin directly, but taken from the West Germanic names. •
Sunday: Old English (), meaning "sun's day". This is a translation of the Latin phrase . English, like most of the
Germanic languages, preserves the day's association with the sun. Many other European languages, including all of the
Romance languages, have changed its name to the equivalent of "the Lord's day" (based on Ecclesiastical Latin ). In both West Germanic and North Germanic mythology, the Sun is personified as
Sunna/Sól. •
Monday: Old English (), meaning "Moon's day". This is equivalent to the Latin name . In North Germanic mythology, the Moon is personified as
Máni. •
Tuesday: Old English (), meaning "Tiw's day".
Tiw (Norse ) was a one-handed god associated with single combat and pledges in
Norse mythology and also attested prominently in wider
Germanic paganism. The name of the day is also related to the Latin name , "Day of
Mars" (the Roman god of war). •
Wednesday: Old English () meaning the day of the Germanic god
Woden (known as
Óðinn among the North Germanic peoples), and a prominent god of the Anglo-Saxons (and other Germanic peoples) in England until about the seventh century. This corresponds to the Latin counterpart , "Day of
Mercury", as both are deities of magic and knowledge. Importantly, both are also
psychopomps, carrying the souls of the dead to the afterlife. The German
Mittwoch, the Low German , the
miðviku- in Icelandic and the Finnish all mean "mid-week". •
Thursday: Old English (), meaning ''s day'. means
thunder or its personification, the Norse god known in Modern English as
Thor. Similarly Dutch , German ('thunder's day'), Finnish , and Scandinavian ('Thor's day'). "Thor's day" corresponds to Latin , "day of
Jupiter" (the Roman god of thunder). •
Friday: Old English (), meaning the day of the Anglo-Saxon goddess . The Norse name for the planet Venus was , '
Frigg's star'. It is based on the Latin , "Day of
Venus". •
Saturday: named after the Roman god
Saturn associated with the Titan
Cronus, father of Zeus and many Olympians. Its original Anglo-Saxon rendering was (). In Latin, it was , "Day of Saturn". The Nordic
laugardagur,
leygardagur,
laurdag, etc. deviate significantly as they have no reference to either the Norse or the Roman pantheon; they derive from
Old Nordic , literally "washing-day". The German (mainly used in northern and eastern Germany) and the Low German mean "Sunday Eve"; the German word derives from the name for
Shabbat.
Adoptions from Germanic Sami languages have weekday names influenced from neighboring languages, with a majority of weekday names being from Germanic-Norse origin.
Hindu tradition Hindu astrology uses the concept of days under the regency of a planet under the term
vāsara/vāra, the days of the week being called
sūrya-/ravi
-/āditya
, chandra-/soma-, maṅgala-, budha-, guru-/bṛhaspati-, śukra-, and
śani-vāsara.
śukrá is a name of Venus (regarded as a son of
Bhṛgu);
guru is here a title of
Bṛhaspati, and hence of Jupiter;
budha "Mercury" is regarded as a son of
Soma, that is, the Moon. Knowledge of
Greek astrology existed since about the 2nd century BC, but references to the
vāsara occur somewhat later, during the
Gupta period (
Yājñavalkya Smṛti, c. 3rd to 5th century AD), that is, at roughly the same period or before the system was introduced in the Roman Empire.
In languages of the Indian subcontinent Southeast Asian languages The
Southeast Asian tradition also uses the Hindu names of the days of the week.
Hindu astrology adopted the concept of days under the regency of a planet under the term
vāra, the days of the week being called
āditya-, soma-, maṅgala-, budha-, guru-, śukra-, and
śani-vāra.
śukrá is a name of Venus (regarded as a son of
Bhṛgu);
guru is here a title of
Bṛhaspati, and hence of Jupiter;
budha "Mercury" is regarded as a son of
Soma, that is, the Moon. }from Sans. āditya
Northeast Asian languages East Asian tradition The
East Asian naming system for the days of the week closely parallels that of the Latin system and is ordered after the "Seven Luminaries" ( ), which consists of the Sun, Moon and the five classical planets visible to the naked eye. 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). The 4th-century AD date, according to the
Cihai encyclopedia, is due to a reference to Fan Ning (), an astrologer of the
Jin dynasty. The renewed adoption from Manichaeans in the 8th century AD (
Tang dynasty) is documented with the writings of the Chinese Buddhist monk
Yijing and the Ceylonese Buddhist monk
Bu Kong. The Chinese transliteration of the planetary system was soon brought to
Japan by the Japanese monk
Kobo Daishi; surviving diaries of the Japanese statesman
Fujiwara no Michinaga show the seven-day system in use in
Heian Period Japan as early as 1007. 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. In China, with the founding of the
Republic of China in 1911, Monday through Saturday in China are now named after the luminaries implicitly with the numbers. :
Pronunciations for Classical Chinese names are given in Standard Chinese. == Numbered days of the week ==