In a vast number of languages, the names given to the seven days of the week are derived from the names of the seven classical planets which were in turn named after contemporary Hellenistic deities. This system was introduced by the Sumerians and later adopted by the Babylonians from whom the Roman Empire adopted the system during late antiquity. In some other languages, the days are named after corresponding deities of the regional culture. The seven-day week was adopted in early Christianity from the Hebrew calendar, and gradually replaced the Roman internundinum. Eight-day and seven-day weeks existed side-by-side until the Emperor Constantine made the seven-day week official in AD 321; thereafter, the seven-day week spread throughout the Roman Empire and eventually through Christian cultures around the world.
The history of the seven-day week can be traced to ancient civilizations. Sunday remained the first day of the week, being considered the day of the sun god Sol Invictus and the Lord's Day, while the Jewish Sabbath remained the seventh. Most historians agree the seven-day week dates back to Babylonians who started using it about 4,000 years ago. The number 7 was sacred to the Babylonians. Emperor Constantine of the Roman Empire made the Day of the Sun (, "Sunday") a legal holiday centuries later.
In the international standard ISO 8601, Monday is treated as the first day of the week, but in many countries it is counted as the second day of the week.
Days named after planets
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").Nerone Caesare Augusto Cosso Lentuol Cossil fil. Cos. VIII idus Febr(u)arius dies solis, luna XIIIIX nun(dinae) Cumis, V (idus Februarias) nun(dinae) Pompeis. Robert Hannah, "Time in Written Spaces", in: Peter Keegan, Gareth Sears, Ray Laurence (eds.), Written Space in the Latin West, 200 BC to 300 AD, A&C Black, 2013, p. 89. 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?"E. G. Richards, Mapping Time, the Calendar and History, Oxford 1999. p. 269 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:
Day SundaySun MondayMoon TuesdayMars WednesdayMercury ThursdayJupiter FridayVenus SaturdaySaturn Greek Book 37, Sections 16-19. English translation. Latin
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).
Day(see Irregularities) Sunday Monday Tuesday Wednesday Thursday Friday Saturday Aragonese Aranese Occitan Asturian Catalan Corsican French Friulian Galician Italian Ladin (Gherdëina) Ladin (Val Badia) Ligurian Lombard (Bresciano) Lombard (Milanese) Neapolitan Occitan Portuguese Romanian Romansh (Putèr) Romansh (Rumantsch Grischun) Romansh (Surmiran) Romansh (Sursilvan) Romansh (Sutsilvan) Romansh (Vallader) Sardinian etc.Also etc.Also etc.Also etc.Also etc.Also Sicilian Spanish Venetian
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.
Day(see Irregularities) Sunday Monday Tuesday Wednesday Thursday Friday Saturday Irish Manx Old Irishreplacing a system of n "one-, three-, five-, ten-, or fifteen-day periods" (>Dáibhí Ó Cróinín, 2003, p. 7). MS. 17 (now held at St. John's College, Oxford), dating at least from 1043, records five-week-day lists, which it names as follows: secundum Hebreos (according to the Hebrews); secundum antiquos gentiles (according to the ancient gentiles, i.e., Romans); secundum Siluestrum papam (according to Pope Sylvester I, i.e., a list derived from the apocryphal Acta Syluestri); secundum Anglos (according to the English); secundum Scottos (according to the Irish). Ó Cróinín has Diu luna as "represent[ing] the transitional form between Latin dies lunae and the later, Classical Old Irish dia luain ... a translation of, not a calque on, the Latin ... [It] would seem to reflect a pre-assimilation state in respect of both words," Dáibhí Ó Cróinín, 2003, p. 13 "The Irish word perhaps derives from Latin forms where cases other than the genitive were used, e.g., Marte."Dáibhí Ó Cróinín, 2003, p. 15 A form unique to Irish, meaning uncertain. In Old Irish, íath can mean "land." A "very old" word for Wednesday, Mercúir (borrowed from the Latin (dies) Mercurii), does occur in early Leinster poems but Ó Cróinín is of the belief that Diu eathamon "reflects a still older Irish word for 'Wednesday.'" A form unique to Irish. Ó Cróinín writes, "I suggest that it means simply 'on Thursday' ... it is temporal dat. of an n-stem (nom. sg. etham, gen. sg. ethamon – as in our Oxford list – and acc./dat. sg. ethamain)." (2003, p. 17) He furthermore suggests that etham ('arable land') "may be a noun of agency from ith (gen. sg. etho), with a meaning like corn-maker or some such thing; Diu eathamon might then be a day for sowing seed in a weekly regimen of activities such as we find in Críth Gablach." Dáibhí Ó Cróinín, 2003, p. 17. The form Ethomuin is found in Rawlinson B 502. A form unique to Irish, its meaning unclear. Old Irish (later) Scottish Gaelic
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.
Day Sunday Monday Tuesday Wednesday Thursday Friday Saturday Breton Cornish Welsh
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.
Day Sunday Monday Tuesday Wednesday Thursday Friday Saturday Albanian
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.
Day(see Irregularities) Sunday Monday Tuesday Wednesday Thursday Friday Saturday ApI Interlingua sol-die luna-die marte-die mercurio-die jove-die venere-die Idiom Neutral soldi lundi marsdi merkurdi yovdi vendrdi saturndi Ido INTAL sundi lundi mardi merkurdi jodi venerdi saturdi Interlingue Lingua Franca Nova Mondial soldi lundi mardi mierdi jodi vendi samdi Novial Reform-Neutral soldí lundí marsdí mercurdí jovdí vendredí saturndí Uropi Soldia Lundia Mardia Mididia Zusdia Wendia Sabadia
Day(see Irregularities) Sunday Monday Tuesday Wednesday Thursday Friday SaturdayChamorro Esperanto Filipino Interlingua Māori [not celestially named] ( = "holy day") ( = day + Moon) ( = day + Mars) ( = day + Mercury) ( = day + Jupiter) ( = day + Venus) [not celestially named] ( = "washing day") Neo Romániço Domínico Lun-dio Marti-dio Mercurii-dio Jov-dio Véner-dio Sábato Universalglot diodai lundai mardai erdai jovdai vendai samdai
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.
Day(see Irregularities) Sunday Monday Tuesday Wednesday Thursday Friday Saturday Afrikaans Dutch Old English Old Saxon Scots West Frisian