What are the origins of the names of the days of the week?

Search: names days of week

Why: In Best Awful by Carrie Fisher (which is not good, btw; why am I reading it):

The history of the names of the days of the week fascinated her most of all; discovering they were named for Norse gods, ones once deemed Pagan by those finicky priests.

Answer: They come from all different places! Let's start at the beginning:

Sunday

• from Latin dies Solis, "sun's day," a Pagan Roman holiday - German: Sonntag, Dutch: zondag
• Romance languages use Latin root Dominica, "Day of God" - Spanish: domingo, French: dimanche
• Greek Hemera Heliou, "day of Helios" (the Sun)

Monday

• from Anglo-Saxon monandaeg, "the moon's day" - German: Montag, Dutch: maandag
• Latin dies lunae, "day of the moon" - Spanish: lunes, French: lundi
• Greek Hemera Selenes, "day of Selene" (goddess of the moon)

Tuesday

• named for Norse Tyr, Tiw, or Tiu (god of war) - Danish: tirsdag, Sweden: tisdag
• Latin dies Martis, "day of Mars" (Roman god of war) - Spanish: martes, French: mardi
• Greek Hemera Areos, "day of Ares" (Greek god of war)
• (German was originally Ziostag, also name for Tyr, but is now Dienstag, "Assembly Day")

Wednesday

• named for Anglo-Saxon Woden or Norse Odin (leader of the Wild Hunt, god of fury and death and wisdom and poetry) - Dutch: woensdag, Danish: onsdag
• Latin dies Mercurii, "day of Mercury" (messenger, god of trade) - Spanish: miércoles, French: mercredi
• Greek Hemera Hermu , "day of Hermes" (messenger, god of commerce)
• German Mittwoch, "middle of the week"

Thursday

• named for Norse Thor (god of thunder) - Danish: torsdag
• Germanic form of name is Donar - Dutch: donderdag, German: Donnerstag
• Latin dies Jovis, "day of Jove / Jupiter" (god of the sky and thunder) - Spanish: jueves, French: jeudi
• Greek Hemera Dios, "day of the god" (maybe Zeus?)

Friday

• named for Norse Frigg or Freya, wife of Woden (goddess of love & beauty, goddess of goddesses) - Dutch: vrijdag, German Freitag
• Latin dies veneris, "day of Venus" (goddess of love) - Spanish: viernes, French: vendredi
• Greek Hemera Aphrodites, "day of Aphrodite" (goddess of love)

Saturday

• Latin dies Saturni, "day of Saturn" (god of agriculture) - Dutch: zaterdag, German: Samstag, Spanish: sábádo, French: samedi
• Greek Hemera Kronu, "day of Cronus" (father of Zeus)
• some Scandinavian languages use a name that means "Washing Day" - Danish: Lørdag, Swedish: Lördag

Source: Encyclopedia Mythica, Crowl.org, Origin of Day Names

The More You Know: And in Japanese!

Sunday - nichiyobi, "sun day"
Monday - getsuyobi, "moon day"
Tuesday - kayobi, "fire day
Wednesday - suiyobi, "water day"
Thursday - mokuyobi, "wood day"
Friday - kinyobi, "gold day"
Saturday - doyobi, "earth day"