Why Romanian weekdays still carry five Roman gods

luni to vineri: what the dictionaries say

Five gods, five working days

Romanian keeps the Latin planetary week almost untouched from Monday to Friday. Each name comes from its planet's day — [dies] Lunae, Martis, Mercuris, Jovis, Veneris — and the planets carry gods' names.

luni *lunis

the Moon

Luni comes from *lunis (= lunae [dies]), the day of the Moon: so DEX gives it, with the asterisk of reconstructed forms. The -is ending aligned itself with Martis, Jovis, Veneris (Scriban). It is also the only day named after a body sometimes seen by daylight.

marți martis

Mars

Marți comes from [dies] Martis, the day of Mars, god of war. DEX gives plain martis [dies]. French mardi and Italian martedì keep the same god.

miercuri mercuris

Mercury

Miercuri comes from [dies] Mercuris, the day of Mercury, messenger of the gods. DEX gives mercuris [dies]; DER gives Lat. Mercurii (dies), as does Șăineanu. The fastest god holds the middle of the week.

joi jovis

Jupiter

Joi comes from [dies] Jovis, the day of Jupiter, master of the gods. DEX gives Lat. [dies] Jovis. French jeudi and Spanish jueves keep the same supreme god.

vineri veneris

Venus

Vineri comes from [dies] Veneris, the day of Venus, goddess of love. DEX gives Lat. Veneris [dies]. French vendredi and Italian venerdì keep the same goddess.

Why the gods stand scrambled

The arithmetic that scrambled the week

The planets had a fixed ladder, from the slowest to the fastest: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon. Each hour of the day belonged, in turn, to one planet, and the planet of the first hour named the day. A day holds twenty-four hours, and twenty-four means three full rows of seven plus three hours. So each day starts three rungs lower on the ladder, and the row of days comes out scrambled.

24 = 3×7+3

The Chaldean ladder, from the slowest planet to the fastest:

1. ♄ Saturn
2. ♃ Jupiter
3. ♂ Mars
4. ☉ Sun
5. ♀ Venus
6. ☿ Mercury
7. ☽ Moon

24 mod 7 = 3

The wheel of the planets: after every 24 hours, the hand jumps three rungs.

Run the wheelOne hourOne day (+24 hours)From the start

No hour running yet: run the wheel, step hour by hour, or jump whole days.

The mechanism, in brief: 24 = 3×7+3 — each day starts three rungs lower, and the day rulers come out Saturn, Sun, Moon, Mars, Mercury, Jupiter, Venus.

The day rulers, in the row attested at Pompeii:

1. ♄ Saturday
2. ☉ Sunday
3. ☽ Monday
4. ♂ Tuesday
5. ☿ Wednesday
6. ♃ Thursday
7. ♀ Friday

The wheel keeps no one's side: wherever you start, 24 hours still mean three whole rows plus three rungs. The row above opens with Saturday because that is how the Pompeii graffito, CIL IV 6778–6779, shows it.

The mechanism is ancient, not a modern explanation. Cassius Dio describes it in Roman History 37.18–19, and Vettius Valens devotes a substantial section of his Anthologies to the planetary week, around the middle of the second century.

Why sâmbătă is not Saturn's day

Sâmbătă is the only day whose road into Romanian is disputed. DEX derives it from Slavic sonbota, and MDA2 from Slavic сѫбота; NODEX gives both forms, lat. sambata, sl. sonbota.

But DER (Ciorănescu) argues for Latin sambatum — for sabbatum — and calls the Slavic derivation “improbable”. Șăineanu reconciles the camps: Slav. SOBOTA (from lat. SABBATUM).

Here Romanian refused the planet. In the planetary week, Saturn's day opens the row; but Christians kept the name of the Hebrew Sabbath, and the Romanian sâmbătă is not Saturn's day.

The exact route — straight from Latin or through Slavic — stays disputed between dictionaries.

The renamed day

Where the word duminică comes from

Duminică comes from [dies] dominica, the Lord's day. DEX gives Lat. [dies] dominica, and Șăineanu calls it the only Christian name among the weekday names. Before the rename, the day was called dies solis, the day of the Sun.

No single renaming date is known. The oldest disputed attestation of kuriakē, the Lord's day, stands in Revelation 1:10. The Didache 14 mentions it, and Clement, around 190, is the first to tie the Lord's day plainly to Sunday. Constantine's own law of 321 still calls it dies solis.

The 321 law, in its own words

Emperor Constantine gave Sunday rest the force of civil law. Below stands the text preserved in Codex Justinianus 3.12.2, with the translation beside it. Judges, townspeople and craftsmen rest; farmers are exempt, lest they miss the sowing season.

the farmers' exemption

The law is dated 3 March 321, by its subscript: pp. V non. Mart., under the consuls Crispus II and Constantine II. Some modern works write 7 March; the subscript date stays 3 March 321. The law is addressed to Helpidius and applied first in the West; after 324, in the East as well.

The legal story does not stop in 321: the same Codex title gathers laws of later emperors, and only in 389 does a law mention, beside dies solis, the name dominicos too (3.12.6).

The Latin follows the published Codex Justinianus text; the Romanian translation by Marius Comper stands in the Romanian edition of this page.

Who refused the Roman deal

The mirrors: three refusals

Not everyone kept the gods of Rome. Germanic speakers swapped four gods for their own, Slavs numbered the days instead of dedicating them to gods, and the Portuguese numbered them too, after a bishop who refused the pagan names.

Germanic speakers swapped four gods

English translated the Sun and the Moon with native words, replaced four gods with its own, and borrowed a single Roman name: Saturn. The table shows what happened to each Latin name.

Friday is, in Old English, frigedæg — Frīg's day, Frīg being the Germanic goddess of marriage; dictionaries relate her conventionally to Frigg. Freyja belongs to Norse traditions: some early Icelandic writers used Freyjudagr for Friday.

Slavs numbered the days

Russian dedicates the days to no god. It numbers them from Sunday: the second, the middle, the fourth, the fifth. Monday comes after Sunday, Saturday keeps the Sabbath, and Sunday is the Resurrection.

Meanings follow Boris Rosenfeld's commented list (LLULL, 1994), cited under sources.

The Portuguese number them too

Portuguese is the only Romance language in which Monday to Friday are numbered: segunda-feira, terça-feira, quarta-feira, quinta-feira, sexta-feira. Sunday stayed domingo, and Saturday sábado. The numbering comes from liturgical Latin feria — the Church's name for working days — and tradition conventionally ties it to Martin of Braga, the sixth-century bishop who preached against the pagan names of the days.

Four common mistakes

1. The order of the days looks drawn by lot.

   It follows the planetary-hour arithmetic: 24 = 3×7+3. The wheel above shows it from the ladder, with no handwritten list. The Pompeii graffito, CIL IV 6778–6779, already shows the planetary row, before 79.

2. Sunday was Constantine's invention.

   Christians gathered on Sundays more than a century and a half before the law. Justin Martyr writes around 155, in First Apology 67: “on the day called Sunday, all who live in cities or in the country gather together to one place” (Roberts-Donaldson translation). The 321 law made Sunday a civil rest day and still called it dies solis.

3. The seven-day week surely comes from Babylon.

   Not established. Babylonians had lunar schemes, with no fixed seven-day cycle. The link between planets and days is a Hellenistic astrology innovation, and the seven-day week, as a steady measure of time, is an early Roman imperial invention, from the merger of the biblical week with the planetary one.

4. Every English day carries a Norse god.

   No day is wholly Norse: the Sun and the Moon are translated, Saturn is borrowed whole from Rome, and Tiw, Woden, Thunor and Frīg are Germanic gods set in the Romans' places. The Germanic table above shows exactly which.

Who named your day?

Five cards, five days. Pick the right answer in each card.

Further, on the same shelf

What we do not know (and say so)

• Where the seven-day week comes from. The Babylonian hypothesis stays unproven: not established.
• When duminică took the name dominica. We hold scattered attestations, not a single date.
• Which road brought the Sabbath into Romanian: DEX and MDA2 give Slavic sonbota, DER gives Latin sambatum and calls the Slavic derivation “improbable”. The dispute stays open.
• How much Frigg and Freyja overlap behind Friday. The Old English form is frigedæg, Frīg's; the Freyja confusion comes from the north.
• How much of the Portuguese numbering is personally Martin of Braga's. His campaign against the pagan names is attested; the language's move to feria is a matter of tradition, not of minutes.

Five pagan gods, one Sabbath, one Lord's day: that is what you say, every week, without thinking.

Sources

Dictionaries first, then the law and the ancient texts, then the studies. Every risky claim points to its source.

Dictionaries

• luni: DEX
• marți: DEX
• miercuri: DEX
• joi: DEX
• vineri: DEX
• sâmbătă: DEX
• duminică: DEX

The law and the ancient texts

• Codex Justinianus 3.12.2, the Latin text
• Philip Schaff on the Sunday law
• Justin Martyr, First Apology 67
• Constantine's Sunday legislation (Cambridge)

The planetary week

• Bultrighini and Stern, the week chapter (PDF)
• Sacha Stern, chapter 1 (PDF)
• Cassius Dio, Roman History 37

The mirrors

• Sunday: calqued on dies Solis (etymology dictionary)
• Saturday: borrowed Saturn (etymology dictionary)
• Friday: frigedæg, Frīg's (etymology dictionary)
• The Slavic day-names (Rosenfeld, LLULL 1994)
• Feria, the Church's name for weekdays (Catholic Encyclopedia)
• Martin of Braga (Catholic Encyclopedia)
• Bishops against the pagan names (Kahlos, 2021)

Background

• dies dominica (Encyclopedia.com)
• The calendars project (UCL)

Type: Fraunces, Newsreader and Atkinson Hyperlegible, under the SIL Open Font Licence.