Every week, you cycle through moody Mondays, hump-day Wednesdays, and T.G.I. Fridays. The seasons may change, but the days of the week stay consistent. So, where did these days of the week come from? The lengths of our days, months, and years were determined based on the movements of the sun and moon, and the names of the days have similar celestial roots.
It's All Greek to Me
The seven-day week has been an established structure for about 4,000 years, but the names of the days have gone through an evolution. Going back to the time of ancient Greece, the days were named after celestial bodies: the five known planets (named after gods) and the moon and the sun.
The Romans adopted a similar system and changed some names accordingly by replacing Greek deities with Roman gods. Later, when adapting those names into Old English, the Anglo-Saxons sprinkled their own flavor into the mix, giving us the names we now know and love to cross out on the calendar.
Decoding the Days
Here’s an easy one to start: The Ancient Greeks deemed a particular day the "day of the sun" — "hemera helio." The Latin version was "dies solis," and the Old English word was "sunnandæg." Eventually, that evolved into Sunday.
Next up, we have the "day of the moon" — "hemera selenes." In Latin, this became "dies lunae." The Old English version was "monandæg," which left us with Monday.
Now we have some god-inspired names. The day after Monday was given to Ares, the Greek god of war. Then the Romans switched it to Mars, their god of war, and the Saxons did the same with their god of war and sky, Tiu. Tiu’s day (Old English "tiwesdæg") is the reason that we have the word Tuesday.
Hermes, the Greek god of commerce, invention, and trickery, earned the next day. He was replaced with Mercury, the Roman god of commerce and science. However, the Saxons decided to go in a different direction. They chose Woden, the leader of the hunt. Woden’s day ("wodnesdæg") is known as Wednesday.
The Greeks were feeling bold and named the next day after Zeus, the leader of the gods. The Romans followed suit, giving the day to Jupiter, their supreme god. The Old English speakers again had a slightly different plan; they elected to honor the Saxon/Norse god of thunder, Thor, with "thursdæg." Fast-forward 1,500 years and we’re celebrating (thirsty) Thursday.
Ancient Greek calendar-makers must have loved Fridays as much as we do. They named the day after Aphrodite, the goddess of love and beauty. The Roman-equivalent goddess was Venus, and the Saxons had Freya. Her day was known as "frigadæg," which turned into Friday.
Finally, we have the weekend. The Greeks honored Cronus, father of Zeus, on the day after Friday, while the Romans decided to do their own thing and honor the god of agriculture, Saturn. The Saxons must not have been too bothered by this, as they went with a similar name. "Sæternesdæg" turned into Saturday.