And the Roman Catholic Church renamed Dies Saturnae to Sabbato in Latin, and Dies Soli to Dominca, and Monday through Friday as Feria II-VI.
I have proof right here:
Notice how Saturday is referred to as Sabbato (abbreviated as Sabb).
But don’t take my word for it, I asked a fresh chatGPT session to explain how the names of weekdays changed under the Roman Catholic and Eastern Orthodox churches:
Christianity did not preserve the pagan weekday system in its liturgical languages
The claim that Catholic or Orthodox Christianity must be “pagan” because English speakers say words such as “Thursday” or “Saturday” confuses inherited
vernacular vocabulary with the terminology actually adopted by the Church.
The ancient Roman planetary week used the following names:
| Modern day | Pagan Roman name | Meaning |
|---|
| Sunday | Dies Solis | Day of the Sun |
| Monday | Dies Lunae | Day of the Moon |
| Tuesday | Dies Martis | Day of Mars |
| Wednesday | Dies Mercurii | Day of Mercury |
| Thursday | Dies Iovis | Day of Jupiter or Jove |
| Friday | Dies Veneris | Day of Venus |
| Saturday | Dies Saturni | Day of Saturn |
The ancient Church did not make this planetary nomenclature its normal liturgical system. In ecclesiastical Latin, the Roman Church used:
| Day | Ecclesiastical Latin | Meaning |
|---|
| Sunday | Dominica or Dies Dominica | The Lord’s Day |
| Monday | Feria II or Feria secunda | Second day |
| Tuesday | Feria III or Feria tertia | Third day |
| Wednesday | Feria IV or Feria quarta | Fourth day |
| Thursday | Feria V or Feria quinta | Fifth day |
| Friday | Feria VI or Feria sexta | Sixth day |
| Saturday | Sabbatum | The Sabbath |
Thus, in the liturgical Latin of the Roman Church, the days of Mars, Mercury, Jupiter, Venus and Saturn became numbered ferial days and the Sabbath. The day of the Sun became
Dominica, the Lord’s Day, commemorating the Resurrection of Christ.
The Orthodox Greek terminology is equally explicit:
| Day | Greek | Meaning |
|---|
| Sunday | Κυριακή — Kyriakē | The Lord’s Day |
| Monday | Δευτέρα — Deutera | Second |
| Tuesday | Τρίτη — Tritē | Third |
| Wednesday | Τετάρτη — Tetartē | Fourth |
| Thursday | Πέμπτη — Pemptē | Fifth |
| Friday | Παρασκευή — Paraskevē | Preparation |
| Saturday | Σάββατον — Sabbaton | Sabbath |
Friday is called “Preparation” because it was the day of preparation for the Sabbath, terminology found in the New Testament itself. Sunday is not the “day of the Sun,” but Κυριακή, the Lord’s Day.
Church Slavonic, used liturgically throughout much of the Slavic Orthodox world, likewise contains no series of names honouring Mars, Mercury, Jupiter, Venus or Saturn:
| Day | Church Slavonic | Meaning or derivation |
|---|
| Sunday | недѣ́лѧ — nedělja | The day of no work or rest |
| Monday | понедѣ́льникъ — ponedělnikŭ | The day after Sunday |
| Tuesday | вто́рникъ — vtornikŭ | Second day |
| Wednesday | среда̀ — sreda | Middle of the week |
| Thursday | четверто́къ — chetvertokŭ | Fourth day |
| Friday | пѧто́къ — pętokŭ | Fifth day |
| Saturday | сꙋббѡ́та — subbota | Sabbath |
English presents a different history. Germanic peoples translated or replaced several Roman planetary names with the names of roughly corresponding Germanic gods: Mars with Tiw, Mercury with Woden, Jupiter with Thor, and Venus with Frigg. English therefore inherited Tuesday, Wednesday, Thursday and Friday. It also retained Sun-day, Moon-day and Saturn-day.
That linguistic inheritance does not mean that Christians worship those deities. A word’s remote etymology does not determine the religion of everyone who later speaks the language. Otherwise, anyone who says “January” would be worshipping Janus, anyone who says “March” would be worshipping Mars, and anyone mentioning the planet Jupiter would thereby become a pagan.
More importantly, when Christians developed their own ecclesiastical terminology, they did precisely what this criticism alleges they failed to do:
[]The Roman Church replaced the planetary names with Dominica, numbered feriae, and Sabbatum.
[]The Greek Church used the Lord’s Day, numbered days, Preparation and Sabbath.
- The Slavonic Orthodox tradition used rest, numerical or positional names, and Sabbath.
Therefore, the continued existence of pagan-derived words in English proves something about the history of the English language. It proves nothing about Catholic or Orthodox worship.
The same principle appears in Scripture. The New Testament uses ordinary Greek words produced within a pre-Christian culture, yet no Christian concludes that using the Greek language constitutes worship of the Greek gods. Christians may replace pagan terminology when doing so serves the Faith—as the Churches demonstrably did with their weekday systems—but Christianity has never taught that merely pronouncing a word with a pagan etymology is an act of idolatry.
In summary: the pagan Romans had days of the Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn. The historic Churches gave the Christian world the Lord’s Day, the biblical sequence of numbered days, the Preparation and the Sabbath. Appealing to modern English weekday names while ignoring the actual Latin, Greek and Slavonic ecclesiastical terminology is therefore historically misleading.