Why Wednesday?

This wheel is the entire book at a glance. It has seven slots — one per day, each colored by the metal that ancient people paired with its planet (gold for the Sun, silver for the Moon, iron for red Mars…). The panel beside it takes a single slot, Wednesday's, and shows what ten languages did with it.

Read the small notes on each row: some languages still show the planet plainly — Spanish miércoles is Mercury, barely disguised. Some replaced the planet with a number. Some replaced it with a description. And English replaced the god himself with a different god. Those four moves are the whole story, and every day name in this book uses one of them.

Go out on a clear night and memorize where the stars are. Come back a week later: every constellation is exactly where you left it. The stars move together, like a painting on a slowly turning ceiling — except for seven lights that drift across the painting. The Sun, the Moon, and five bright "stars" that refuse to keep formation. The Greeks called them planētes — "the wanderers." We call them planets.

Ancient astronomers timed each one: how long it takes to cross the whole sky and come back to where it started. Then they ranked them, slowest at the top. That ladder — measured with nothing but patience — is the machine the week was built from.

Look at the ladder again. If the week simply copied the sky, slow Saturn's day would be followed by Jupiter's, then Mars's. It isn't — Saturday is followed by Sunday. The week runs in a scrambled order, and the scramble had a logic.

Ancient astrologers gave every hour of the day to a wanderer, cycling down the ladder on repeat: on Saturday, Saturn rules hour 1, Jupiter hour 2, Mars hour 3, and so on, wrapping back around to Saturn again. Whichever wanderer ruled a day's first hour owned the whole day — that was the rule.

Now count. A day has 24 hours, and 24 is three full trips around seven with three left over. So Saturn rules Saturday's hours 1, 8, 15 and 22; Jupiter takes 23; Mars takes 24 — and the next day's first hour lands on the Sun. Saturday hands off to Sunday. Three rungs along, every single day. Press the button and watch the week assemble itself.

When Rome's seven-day week spread across the world, every language inherited the same seven slots — and a decision: what do you call days named after somebody else's gods? Across the ten languages in this table and two thousand years of history, there have only ever been four answers.

The chart under the cards shows all ten languages making that decision — one row per language, seven cells per row, Sunday through Saturday. Solid teal: the planet survived. Ink: a god was swapped in. Grey: a number took the slot. A dashed, empty cell: the planet is gone entirely.