What day of the week is it? If I were to say “Day of the Moon,” you might start worrying about what pagan cult I had joined. However, were I to say “Moon-day” with a strong mumble, you would hardly notice. In fact, according to the original Greco-Roman tradition of the 7-day week (replacing the 8-day nundinal cycle), each day was named after a heavenly body:
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 Jovis (Day of Jupiter)
Friday: Dies Veneris (Day of Venus)
Saturday: Dies Saturni (Day of Saturn)
In nearly all Romantic languages, these Latin names are the basis for modern weekday titles (except Sunday which was later christened “the Day of the Lord” or dies Dominica). But English is not wholly a Romantic language, and clearly English weekday names do not follow this convention. Instead, English as we know it today has origins as a Germanic language. So, if we have Germanic roots, where do our weekday names come from?
Those familiar with Greek/Roman mythology will recognize that the heavenly bodies used to name the weekdays are also associated with major Roman deities. When the Germanic peoples adopted the Roman system, they did much the same thing, and renamed each of their weekdays to correspond with the Germanic/Norse gods (known as interpretatio germanica). Unfortunately, those mythologies did not travel through time as successfully due to conflicts with Christian religious teachings. To this day, however, our weekday titles remain homages to these forgotten deities: Sunna/Sol, Mani, Tiw/Tyr, Wodan/Odin, Thor, and Frigg.
Sunday
Old English: Sunnandæg
Meaning: Sun’s Day
God/Goddess: Sunna/Sol
The Germanic languages maintained the original pagan/sun associations of the day, and named Sunday after the Sun’s personified goddess, Sol. Also known as Sunna in Old High German, Sol is the sister of Mani (the Moon) and daughter of Muldilfari. Each day she rides through the sky pulled in a chariot by two horses, Alsvid (“all-swift”) and Arvak (“early riser”) while pursued by Skoll, a monstrous wolf. Occasionally, we perceive solar eclipses when Skoll gets close enough to nip at the Sol’s heels. When Sol is finally caught and swallowed, it will bring about the end of the world (known in Norse Mythology as Ragnarok). However, before that happens, Sol will give birth to a daughter (sometimes also known as Sunna) who will bring peace and love to a reborn world.
Monday
Old English: Mōnandæg
Meaning: Moon’s Day
God/Goddess: Mani
Similar to offering one weekday to the Sun’s personified deity, the Germanic languages named a second weekday after the Moon’s personification, Mani. Mani is the brother of Sol (the Sun) and daughter of Muldilfari. He rides through the night time sky in his horse-drawn chariot, determining the degree to which it waxes and wanes. Like his sister, Mani is chased by a giant wolf named Hati until Ragnarok, and similarly produces a lunar eclipse when nearly caught. Additionally, Mani adopted two children, Hjuki and Bil, whom he has charged the task of putting spots on the moon (this tale is the also the origin of the Jack and Jill nursery rhyme).
Tuesday
Old English: Tīwesdæg
Meaning: Tiw’s Day
God/Goddess: Tyr/Tiw
The Latin namesake for dies Marti was the God of War, Mars. Similarly, in the Germanic languages, Tuesday’s namesake was the God of War and Justice, Tyr. Also known by other names such as Tiw and Tiwaz, Tyr was precursor to Odin and later became Odin’s right-hand man. Or at least, he would have been if he had a right hand. Brave but foolhardy, after restraining the great beast Fenrir, Tyr proceeded by sticking his hand into its mouth as a show of goodwill. To this day, Tyr awaits his revenge for the right hand that he is now missing. During Ragnarok (the end of the world), Tyr is foretold to kill the hound guardian of Hell, Garm, but will die of wounds inflicted during the combat. Still, impressive given his physical shortcomings.
Wednesday
Old English: Wōdnesdæg
Meaning: Wodan’s Day
God/Goddess: Wodan/Odin
The greatest of all Norse gods, Odin earned Wednesday as his namesake. Also read as Woden/Wodan/Wotan and known as the Allfather, Odin was the king of Asgard, ruler over the Aesir (the greatest Norse gods), and Lord of War, Death, and Knowledge. He is known to travel secretively across the world as an old man wearing a wide-brimmed hat (think Gandalf), and has only one eye after trading his other for a drink from Well of Wisdom at the base of the World Tree, Yggdrasil (during which time we also stabbed and hung himself for nine days). Odin is accompanied by two ravens, Huginn and Muninn, two wolves, Geri (“Greedy”) and Freki (“Ravenous”), and rides into battle atop the eight-legged horse, Sleipnir. He is credited with building our world out of the remains of the frost-giant Ymir, and will unfortunately die during the final battle of Ragnarok after being eaten by the great beast Fenrir. The biggest negative, though, is that Odin requires human sacrifices for worship.
Thursday
Old English: Þūnresdæg
Meaning: Thor’s Day
God/Goddess: Thor
The most famous Norse God to make it to modern times (most likely do to comic books), Thursday is named after the Thunder God, Thor. Son of Odin, Thor is often portrayed as a large man with a red beard and lightning eyes. If he wasn’t strong enough, he also has his belt, Megingjard, which doubles his strength, as well as his hammer, Mjollnir. Though he is known for defending both gods and humans against forces of evil, his biggest enemy is the giant Midgard serpent, Jormungand. During Ragnarok, Thor will finally kill the serpent. Unfortunately, however, he will die from its poisonous bite. Until then, Thor entertains himself by riding across the heavens in a chariot pulled by the goats Tanngrisni (“gap-tooth”) and Tanngnost (“tooth grinder”), leaving thunderstorms in his wake.
Friday
Old English: Frīgedæg
Meaning: Frigg’s Day
God/Goddess: Frigg/Frige
The Greco/Roman tradition named this day after the planet Venus. In Norse Mythology, this same heavenly body was known as “Frigg’s star,” and thus lends credence to this day being named after the Goddess of Marriage and Motherhood, Frigg. Frigg was the wife of Odin and mother of Baldur, whom she attempted to make impervious to harm by taking oaths from every living thing not to hurt him (forgetting only Mistletoe, which led to Baldur’s unfortunate demise due to the scheming of Loki). She also had the power of knowing everyone’s destiny, but was consistently able to resist revealing it to anyone, and maintains the clouds with her spindle and broom. While somewhat housewifely, she also showed great mental prowess when out-witting Odin on multiple occasions.
Saturday
Old English: Sæturnesdæg
Meaning: Saturn’s Day
God/Goddess: Saturn
Saturday was the only one of the seven Greco/Roman weekdays that had its name unedited and remains dedicated to Saturn. The most popular explanation is that the Germanic religions simply didn’t have a deity that was similar enough to Saturn. In Greek mythology, Saturn was originally the God of Agriculture and “Sowing Seeds” before becoming conflated with the Titan Cronus due to Roman thought influences. Eventually he earned a place as father of Jupiter/Zeus. Supposedly under Saturn’s rule prior to Jupiter/Zeus taking over, humans enjoyed a “Golden Age” full of social egalitarianism and bountiful harvests. Thanks a lot, Zeus.
If you are interested in learning more about Norse mythology (or any other mythology for that matter), here are some great sites to check out:
Dooley Noted 
So I guess norse did not have a Saturday , or no one knows what the name was, weren’t they Much older then the greeks or Romans? I am shore that they had more gods and goddesses then any other at the time, not just odin, thor, and lokie, but thats all you ever here about know a days.
In the Scandinavian languages, Saturday’s name doesn’t refer to a deity at all; the Old Norse version meant “bath day” or “washing day”, and probably alluded to people cleaning themselves up the night before going to church.
Saturday was almost certainly connected with Sataere, an Anglo-Saxon Goddess of Spring -thus Sataere’s dag (matching the male agricultural God of the classical pantheon. The Father of Sunna is Mundilfari -not ‘Mudilfari’.