Names of the days of the week

Italian cameo bracelet representing the days of the week, corresponding to the planets as Roman gods: Diana as the Moon for Monday, Mars for Tuesday, Mercury for Wednesday, Jupiter for Thursday, Venus for Friday, Saturn for Saturday, and Apollo as the Sun for Sunday. Middle 19th century, Walters Art Museum

The names of the days of the seven-day week in many languages, including English, are derived from their being named after the classical planets in Hellenistic astrology, a system introduced in the Roman Empire during Late Antiquity. In other languages, the days are numbered, depending on regional tradition either beginning with Sunday or with Monday. In the international standard ISO 8601, Monday is treated as the first day of the week.

Days named after planets

Greco-Roman tradition

Between the 1st and 3rd centuries the Roman Empire gradually replaced the eight-day Roman nundinal cycle with the seven-day week. Our earliest evidence for this new system is a Pompeiian graffito referring to the 6th February (viii idus Februarius) of the year AD 60 as dies solis ("Sunday").^[1] Another early witness is a reference to a lost treatise by Plutarch, written in about AD 100, which addressed the question of Why are the days named after the planets reckoned in a different order from the actual order?.^[2]

The days were named after the planets of Hellenistic astrology, in the order Sun, Moon, Mars (Ares), Mercury (Hermes), Jupiter (Zeus), Venus (Aphrodite) and Saturn (Cronos).

The seven-day week spread throughout the Roman Empire in Late Antiquity. By the 4th century, it was in wide use throughout the Empire, and it had also reached India and China.

The Greek and Latin names are as follows:

Romance languages

The Romance languages preserved the Latin names, except for the names of Sunday, which was replaced by [dies] dominicus, i.e. "Day of the Lord" and of Saturday, which was named for the Sabbath.

Celtic languages

Old Irish adopted the names from Latin, but introduced separate terms of uncertain origin for Wednesday, Thursday and Friday.

Adoptions from Romance

Albanian adopted the Latin terms. Other languages adopted the week together with the Latin (Romance) names for the days of the week in the colonial period. Some constructed languages also adopted the Latin terminology.

Germanic tradition

The Germanic peoples adapted the system introduced by the Romans but glossed their indigenous gods over the Roman deities (with the exception of Saturday) in a process known as interpretatio germanica. The date of the introduction of this system is not known exactly, but it must have happened later than AD 200 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.^[11] 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 Sunnandæg (pronounced [ˈsunnɑndæj), meaning "sun's day." This is a translation of the Latin phrase dies Solis. English, like most of the Germanic languages, preserves the original pagan/sun associations of the day. 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 dies Dominica). In both West Germanic and North Germanic mythology the Sun is personified as a goddess, Sunna/Sól.
• Monday: Old English Mōnandæg (pronounced [ˈmoːnɑndæj]), meaning "Moon's day." This is based on a translation of the Latin name dies lunae. In North Germanic mythology, the Moon is personified as a god, Máni.
• Tuesday: Old English Tīwesdæg (pronounced [ˈtiːwezdæj], meaning "Tiw's day." Tiw (Norse Týr) 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 based on Latin dies Martis, "Day of Mars".
• Wednesday: Old English Wōdnesdæg (pronounced [ˈwoːdnezdæj) meaning the day of the Germanic god Wodan (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. It is based on Latin dies Mercurii, "Day of Mercury." The connection between Mercury and Odin is more strained than the other syncretic connections. The usual explanation is that both Wodan and Mercury were considered psychopomps, or guides of souls after death, in their respective mythologies; both are also associated with poetic and musical inspiration. The Icelandic Miðviku, German Mittwoch, Low German Middeweek and Finnish keskiviikko all mean mid-week.
• Thursday: Old English Þūnresdæg (pronounced [ˈθuːnrezdæj]), meaning 'Þunor's day'. Þunor means thunder or its personification, the Norse god known in Modern English as Thor. Similarly Dutch donderdag, German Donnerstag ('thunder's day'), Finnish torstai, and Scandinavian Torsdag ('Thor's day'). Thor's day corresponds to Latin dies Iovis, "day of Jupiter".
• Friday: Old English Frīgedæg (pronounced [ˈfriːjedæj]), meaning the day of the Anglo-Saxon goddess Fríge. The Norse name for the planet Venus was Friggjarstjarna, 'Frigg's star'. It is based on the Latin dies Veneris, "Day of Venus."
• Saturday: the only day of the week to retain its Roman origin in English, named after the Roman god Saturn associated with the Titan Cronus, father of Zeus and many Olympians. Its original Anglo-Saxon rendering was Sæturnesdæg (pronounced [ˈsæturnezdæj]). In Latin it was dies Saturni, "Day of Saturn." The Scandinavian Lørdag/Lördag deviates significantly as it has no reference to either the Norse or the Roman pantheon; it derives from old Norse laugardagr, literally "washing-day." The German Sonnabend and the Low German words Sünnavend mean "Sunday Eve", the German word Samstag derives from the name for Shabbat.

Indian tradition

Indian 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, i.e. the Moon.^[12] Knowledge of Greek astrology since about the 2nd century BC, but references to the vāra occur somewhat later, during the Gupta period (Yājñavalkya Smṛti, c. 3rd to 5th century), i.e. at roughly the same period the system was introduced in the Roman Empire.

East Asian tradition

The East Asian naming system of days of the week closely parallels that of the Latin system and is ordered after the "Seven Luminaries" (七曜 qī yào), which consists of the Sun, Moon and the five planets visible to the naked eye. The five planets are named after the five elements in traditional East Asian philosophy: Fire (Mars), Water (Mercury), Wood (Jupiter), Metal (Venus), and Earth (Saturn).

The Chinese seem to have adopted the seven-day week from the Hellenistic system by the 4th century, although by which route is not entirely clear. It was again transmitted to China in the 8th century by Manichaeans, via the country of Kang (a Central Asian polity near Samarkand).^[13] The 4th-century date, according to the Cihai encyclopedia, is due to a reference to Fan Ning (範寧 / 范宁), an astrologer of the Jin Dynasty. The renewed adoption from Manichaeans in the 8th century (Tang Dynasty) is documented with the writings of the Chinese Buddhist monk Yi Jing 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 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 numbered one through six, with the reference to the Sun remaining for Sunday (星期日).

Pronunciations for Old Chinese names are given in Modern Standard Chinese.

Numbered days of the week

Days numbered from Sunday

Sunday comes first in order in calendars shown in the table below. In the Judeo-Christian or Abrahamic tradition, the first day of the week is Sunday. Biblical Sabbath (corresponding to Saturday), when God rested from six-day Creation, made the day following Sabbath the first day of the week (corresponding to Sunday). Seventh-day Sabbaths were sanctified for celebration and rest. After the week was adopted in early Christianity, Sunday remained the first day of the week, but also gradually displaced Saturday as the day of celebration and rest, being considered the Lord's Day.

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. While the custom of numbering the days of the week was mostly prevalent in the Eastern Church, Portuguese, due to Martin's influence, came to be the one Romance language where the names of the days come from numbers rather than planetary names.^[14]

Icelandic is a special case within the Germanic languages, maintaining only the Sun and Moon (sunnudagur and mánudagur respectively), while dispensing with the names of the explicitly heathen gods in favour of a combination of numbered days and days whose names are linked to pious or domestic routine (föstudagur, "Fasting Day" and laugardagur, "Washing Day"). The "washing day" is also used in other North Germanic languages, although the planetary names generally are retained.

Days numbered from Monday

The ISO prescribes Monday as the first day of the week with ISO-8601 for software date formats.

The Slavic, Baltic and Uralic languages (except Finnish and partially Estonian) adopted numbering but took Monday rather than Sunday as the "first day".^[15]

Chinese Sunday means "week day" (星期日 or 星期天). Monday is named literally "first day of the (seven-day) week cycle", Tuesday is "second day of the (seven-day) week cycle," and so on. When China adopted the Western calendar Sunday was at the beginning of the calendar week but today Monday is preferred.

A second way to refer to the days of the week is to use the word zhōu (周), meaning "week." Therefore Sunday is referred to as zhōurì (周日), meaning literally, "week sun" and Monday to Saturday are termed accordingly zhōuyī (周一) "first of week," zhōu'èr (周二) "second of week," etc.

Another Chinese numbering system, found in spoken Mandarin and in southern dialects/languages (e.g. Wu, Yue and Min), refers to Sunday as the "day of worship" (lǐbàirì 禮拜日 or lǐbàitiān 禮拜天) and numbers the other days "first [day after] worship" (Monday) through to "sixth [day after] worship" (Saturday). The Chinese word used for "worship" is associated with Christian and Muslim worship.

Days numbered from Saturday

In Swahili the day begins at sunrise rather than sunset, and so offset by twelve hours from the Arabic and Hebrew calendar. Saturday is therefore the first day of the week, as it is the day that includes the first night of the week in Arabic.

Etymologically speaking, Swahili has two "fifth" days. The words for Saturday through Wednesday contain the Bantu-derived Swahili words for "one" through "five." The word for Thursday, Alhamisi, is of Arabic origin and means "the fifth" (day). The word for Friday, Ijumaa, is also Arabic and means (day of) "gathering" for the Friday noon prayers in Islam.

Mixing of numbering and planetary names

In the Žejane dialect of Istro-Romanian, lur (Monday) and virer (Friday) follow the Latin convention, while utorek (Tuesday), sredu (Wednesday), and četrtok (Thursday) follow the Slavic convention.^[17]

There are several systems in the different Basque dialects.^[18]

Notes

Sunday

^☉1 From Latin Dominicus (Christian Sabbath)
^☉2 Holy Day (Christianity)
^☉3 Resurrection (Christianity)
^☉4 Bazaar Day
^☉5 End of the Week (Arabic Sabt = Rest) (Islam)
^☉6 Market Day
^☉7 No Work
^☉8 Full good day
^☉9 Borrowed from English week

Monday

^☽1 After No Work. In Russian also "Day After Week(end)" - see понедельник
^☽2 After Bazaar
^☽3 Head of Week
^☽4 Master (as in Pir, because Muhammad was born on a Monday )

Tuesday

^♂1 Thing (Assembly), of which god Tyr/Ziu was the patron.
^♂2 Second day of the week (cf. Hungarian kettő "two")
^♂4 From Arabic "ath-Thalaathaaʼ" (third day)

Wednesday

^☿1 Mid-week or Middle
^☿2 The First Fast (Christianity)

Thursday

^♃1 The day between two fasts (An Dé idir dhá aoin, contracted to An Déardaoin) (Christianity)
^♃2 Five (Arabic)

Friday

^♀1 The Fast (Celtic) or Fasting Day (Icelandic) (Christianity)
^♀2 Good Friday or Preparation (Christianity)
^♀3 Day of Faith (Islam)
^♀4 Gathering/Assembly/Meeting (Islam) – in Malta with no Islamic connotations

Saturday

^♄1 Shabbat or seventh-day Sabbath (Judeo–Christian)
^♄2 Wash or Bath day
^♄3 Sun-eve (Eve of Sunday)
^♄4 After the Gathering (Islam)
^♄6 Week
^♄7 Half good day

See also

Week wheel for children

• Akan names of the seven-day week, known as Nawotwe
• Bahá'í calendar (section Weekdays)
• Calculating the day of the week
• Seven-day week
• Week
• Work Week

Further reading

• Brown, Cecil H. (1989). "Naming the days of the week: A cross-language study of lexical acculturation". Current Anthropology 30 (4): 536–550. doi:10.1086/203782. JSTOR 2743391. 
• Falk, Michael (1999). "Astronomical Names for the Days of the Week". Journal of the Royal Astronomical Society of Canada 93: 122–133. Bibcode:1999JRASC..93..122F. doi:10.1016/j.newast.2003.07.002. 
• Neugebauer, Otto (1979). Ethiopic astronomy and computus, Österreichische Akademie der Wissenschaften, philosophisch-historische klasse, sitzungsberichte, 347 (Vienna)

External links

• Days of the Week in Chinese, Japanese, and Vietnamese (much history of Western systems too)
• Planetary Linguistics and the Days of the Week — The Definitive Site
• Days of the week and months of the year in many different languages
• The Days of the Week
• The days of the week in various languages
• RSS feed to show names of days in Indian languages
• Days of the week in Spanish

References