To be fair, the Romans called it dies Solis, which is a pretty reasonable-length moniker.

Likewise, Monday was dies Lunae.

That would be the Romans. Roman aqueducts were lined with lead. As were their wine amphoras. They liked the taste it gave wine. They even knew lead is poisonous, but they kind of underestimated its toxicity.

Fun, semi-related, fact: the word plumber is derived from plumbarius, Latin for lead-worker, from plumbum, lead.

A bit random, but that reminds me – ever read Neil Gaiman’s American Gods?
(An American version of) Odin calls himself Wednesday in the novel.
Kinda immediately gives away who he is if you know the origins of the name of the day.

Really? My obvious first guess would be they simply didn’t have an equivalent god…

The modern German Samstag comes from “Sabbath day.”

The Norse called Saturday bath day (no points for guessing why) and that’s the root of its name in modern day Scandinavian languages, and Finnish, Estonian and some other related languages.

Carolus Rex was an alias of Charles XII. I suppose it’s accurate to say he lost his empire.

Also, there doesn’t seem to be a clear consensus of which side fired the bullet that hit him. Or if it even was a bullet – apparently the lack of lead fragments and the exit wound being smaller than the entry wound suggest stray iron grapeshot.

To be fair, I probably got the time line of the Swedish Empire mixed up – I blame history classes back in my day, which felt specifically designed to purge any and all interest in history.

The roman god of the sun was Sol Invictus. And sunday isn’t known as Sol Invictus Day, since that would be a bit of a mouthful to use in daily conversation.
The names of the days where named after the 7 planets of the solar system by the ancient Greeks.
Selene (the Moon), Ares (Mars), Hermes (Mercury), Zeus (Jupiter), Aphrodite (Venus), Cronus (Saturn) and Helios (the sun).
Hold your jokes about the sun and moon not being planets and there being more than 5 planets in the solar system (Pluto doesn’t count, it’s not a planet) this was written by ancient Greeks, the people who also thought lead pipes would work great for their supply of drinking water….
When the idea of the 7 day week was adopted by germanic tribes of barbarians, they used germanic names for the gods, the same gods that would be the roots the latter norse gods are based on. Hence the modern weekdays of:
Moon’s Day
Tyr’s Day
Woden’s Day (old spelling for Odin)
Thurs’s Day (old spelling for Thor)
Frey’s Day
Saturns Day (No, I don’t think anyone knows why that one didn’t get translated)
Sun’s Day
Long story short, it’s older than the vikings, like ALOT older. And certainly older than some incompetent Sweedish prat who’s 2 claims to fame is loosing Carolus’s empire and getting shot in the head by his own men.
I hope that clears things up.

Ah yes, the famous Norse gods, Sun and Moon. ;)

The seemingly obvious answer is viking influence all over northern and central Europe, and possibly the conquests of Charles XII of Sweden.

It’s because the ancient roman calendar had ten months. And a lot of holy days that could be inserted where ever the emperor wanted them during the year.
It became such a bother to keep the dates straight, that eventually, one of the emperors, just lumped the holy days together in two extra months, named them after other emperors, July and August, guess the emperors yourself.
The real question you should be asking yourself is, if we have our calendar from the Romans, why are all but one of the days in the week, named after Norse gods, instead of Roman gods? only day named for a roman god is Saturns day.

Because ancient Roman calendar year began on March 1.

There used to be many different dates that could be considered as the beginning of new year.

September, october, november and december are all the numbers from 7 to 10.

That is a good question Sweetie Belle!