True in many other European languages too. Spanish, Italian, Portuguese come to mind.
In English we derive it from Saturn, which is also a god, but I guess too far removed for us to think about it. AFAIK a fair number of European names for days are derived from pagan gods. Even more if you count the Sun and Moon (Sunday, Monday) as gods, as many historical European cultures would have.
Even Thursday is for Thor, Friday for Freya. Which is to say Germanic gods too, not just Greco-Roman or Hebrew.
And in Romance languages, Sunday is named something derived from dies dominicum, Latin for "day of the Lord".
My favorite weekday names are Japanese:
日曜日 nichiyoubi, "sun-weekday"
月曜日 getsuyoubi, "moon-weekday"
火曜日 kayoubi, "fire-weekday"
水曜日 suiyoubi, "water-weekday"
木曜日 mokuyoubi, "wood-weekday"
金曜日 kinyoubi, "gold-weekday"
土曜日 doyoubi, "soil-weekday"
Aside from Sunday and Monday, these names derive from the elements associated with the planets Mars, Mercury, Jupiter, Venus, and Saturn respectively, as indicated in their Japanese names (kasei, suisei, etc.) -- planets named after the gods who gave the weekdays their names (or their rough Norse equivalents in English).
For anyone else curious, these 7-day planetary weekday names are from the West and are not a Japanese invention. Monday = moon = 月, Sunday = sun = 日 is not a coincidence.
The pairings of elements to planets seems to have been done by the Chinese many centuries ago.
Those element pairings were actually brought into Tang China by the Manichaeans in the 8th century AD. and based on parings originating in Rome from the 1st century AD.
Monday = dies Lūnae = moon = 月
Tuesday = dies Martis = fire = 火
Wednesday = dies Mercuriī = water = 水
Thursday = dies Iovis = wood = 木
Friday = dies Veneris = gold = 金
Saturday = dies Saturnī = earth = 土
Sunday = dies Sōlis = sun = 日
Edit: Looks like China did have the same paring of elements to planets as the Romans did in the form of the 七曜 but they weren't used for days of the week until contact with western civilizations along the silk road until after at least 400 AD. Ancient China simply numbered the 30 or 29 days in their lunar calendar and used groupings of 10 days (旬) but didn't really have a concept of a fixed cycle of days with a day for rest and prayer. The crazy thing is that the east and west somehow came up with the same parings between elements and planets.
Edit2: After a bit more research, looks like I was mistaken about the element parings. Rome was the one that paired planets and their associated gods to days of the week, but China was the one that paired elements to planets, and the two sets of parings mixed together afterwards. The fact that gold/metal was an element should have been a big hint since Ancient Greece only considered 4 classical elements while Ancient China used 5.
As a fun fact, although weekdays are named after Roman gods in Romance languages, Portuguese is a notable exception. It uses a literal translation from the ecclesiastic Latin weekdays, which refers to the days when God worked in creating the world: Monday is "Segunda-feira" (second workday), Tuesday is "Terça-feira" (third workday), and so on.
The weekends had already received Judaic/Christian names, therefore weren't changed and are quite similar to the other Romance languages: Saturday is "Sábado" (derived from Sabbath) and Sunday is "Domingo" (Dominicus, Lord's day in Latin).
Also, early in the Catholic tradition, Sunday the first workday and only Saturday was reserved for religious activities. For this reason, in Portuguese, the week starts in the "second" day.
I wonder why Spanish, with its strong Catholic tradition, uses Roman gods for the weekdays. Especially since Portuguese and Spanish are so closely related languages...
In Portugal, this movement was push forward by the royal court (together with the Catholic church, of course), so Portuguese was the only language to do so. For some reason, the Spanish course didn't follow suit.
> Which is to say Germanic gods too, not just Greco-Roman or Hebrew.
Tuesday through Friday are all named based on the Germanic correspondence for a Roman god, as established by the Romans (Tyr/Odin/Thor/Frigg (not Freya) - for Mars/Mercury/Jupiter/Venus). There was no corresponding Germanic god for for Saturn, so it kept the same name.
The early Quakers considered the use of pagan gods' names-derived days of the week and months of the year to be idolatrous and didn't use them. You still find use of phrases such as 'first day school' and 'on the 21st of the fourth month' sometimes. And my marriage registry entry is dated '17 vii 2010', the traditional Quaker date format. Which at least has the advantage (like ISO format) of being unambiguous!
I think it is still an open question, at least according to this [1]:
> Borrowed from Medieval Latin sabbatum (or from Vulgar Latin *sambatum), from Ancient Greek σάββᾱτον (sábbāton), from Hebrew שַׁבָּת (šabbāṯ, “sabbath”).
It's funny cause in Romanian we're using "sâmbătă" for Saturday, which is pretty damn clause to that Vulgar Latin term "sambatum" (which makes sense, Romanian being a romance language), but our official etymological dictionary [2] gives the old slavic "sonbota" as a source.
