Saturday, named after the Roman deity and planet Saturn, is the only day of the week whose Roman origins are preserved in English. Saturn is the Roman and Italic deity of agriculture, as well as Ops' consort. He is thought to have reigned over the Earth during a period of bliss and morality. His image was kept near those of Jupiter and Mars, who were also associated with agriculture.
In addition to being the god of markets and commerce, Saturn was also believed to have controlled disease and death. His role as a farmer made him necessary for any form of prosperity. Because of this, he was often depicted with a sickle, as a symbol of fertility and harvest.
Saturn's influence is felt throughout the cosmos, especially on other planets. On earth, his influence is seen in the cycles of nature: the rise and fall of crops, the changing seasons. Humans also feel his presence through epidemics, wars, and other forms of disaster. Finally, some claim that Saturday is the day of Saturn because it was on this day that Jesus was crucified.
We use Saturday because it is the only day of the week whose name comes from a Latin word. Once you learn how to read, it's easy to see why Sunday was considered the "day of Christ" by early Christians: It's because Luke 24:44 says that Jesus resurrected on this day!
Saturday is Saturn's day, the day of duty and organization. Saturday is typically spent catching up on housekeeping, homework, and personal concerns, which may be due to Saturn's ability to help us become more balanced and grounded. The ancient Romans honored Saturn by keeping his days of obligation as full as possible. This is likely why Saturday is the most important day of the week—to have enough time to deal with all the responsibilities of life while still having time left over.
Sunday is Jupiter's day, the day of joy and luck. Sunday is typically a day off from work or school, which allows for time to relax and enjoy some leisure activities. The ancients viewed Jupiter as the god of happiness and prosperity, so they probably wanted to save their fun for him.
Monday is Mars' day, the day of war and energy. War begins on Monday because that's when you start fighting for your survival. You must eat daily, find safe shelter, avoid predators, and heal injuries if you want to keep living. This is all part of fighting for your life each and every day. After you've survived Monday, you can start planning for Tuesday's battle.
Tuesday is Venus' day, the day of love and beauty. Love is one of the greatest forces in the universe, so it makes sense that it would have its own special day.
The names of the days of the week in English appear to be a mishmash. Saturday, Sunday, and Monday are named after the celestial bodies Saturn, Sun, and Moon, respectively, while the other days are called after Germanic gods: Tiw's day, Woden's day, Thor's day, and Freya's day.
The order in which they are listed in English is based on their relationship to the sun. Thus, Sun rises on Sunday, and Sunset occurs on Saturday. The moon also has an effect on the tide, so there are tides on all seven days.
The ancient Germans believed that there were only six days of creation, but included the moon in this calculation. They counted from one moon to the next, not including the full moon or new moon.
Monday was originally called Monda'thin, meaning "the first day." This name was changed when the other days were added to the week. Friday was originally called Sabat'thin, which means "the seventh day."
Sunday has been called Jesus' day since the early church fathers because it is said that Christ rose on this day. It is now known as Easter Day.
Saturday has been called Walpurgisnacht ("Woden's night") because it is said that witches go out on this night to dance around a fire singing songs to get their powers back after Christianity became popular.
The name "Sunday," or the day of the Sun, derives from Hellenistic astrology, in which each of the seven planets, known in English as Saturn, Jupiter, Mars, the Sun, Venus, Mercury, and the Moon, was assigned an hour of the day, and the planet that was regent during the first hour of any day of the week gave its name — thus, Saturn ruled the first hour of the week, and hence it was called "Saturn's day."
In Roman mythology, Juno, the queen of heaven, is said to have declared herself the ruler of the world on this day. This is why it is called Jovis Dayum Noveskia, which means "the queen of heaven rules over the world."
In English folklore, if you sleep with your eyes open on Sunday night, then you will be able to see the back of your own head. This is because the Sun is out on Sunday morning, and it is believed that if you look directly at it, you will go blind.
In Christianity, after Pentecost, the seventh day of the week was established as a holy day of rest. It is for this reason that Christians call it "Sabbath" or "the Sabbath."
According to the Hebrew Bible, the Israelites were supposed to rest on the seventh day of every week, but they didn't keep this commandment.