What's in a name? Well, when it comes to the days of the week, we need to go all the way back to Babylon, where ancient astronomers used the seven visible planets and the phases of the Moon to establish a week. The days reflect the names of the gods and goddesses that are associated with planets (Saturn, the Roman god of time and fertility, is associated with Saturday, for example). In English most of the days correspond to Nordic gods (Tuesday, Wednesday, Thursday, Friday), and the others are based off of Roman gods (Saturday, Sunday, Monday).
Regardless of whether we use the Nordic or Roman translation, the idea is the same: There's a special planetary patron for each day of the week. What's more, a person born on a given day of the week may reflect traits associated with the planet that rules that day. Take this once popular children's nursery rhyme called "Monday's Child":
Monday's child is fair of face, Tuesday's child is full of grace, Wednesday's child is full of woe, Thursday's child has far to go, Friday's child is loving and giving, Saturday's child works hard for a living, But the child who is born on the Sabbath day Is bonny and blithe and good and gay.
While not all children have qualities that adhere to this rhyme, it's on to something.
A child born on Monday, named after the emotional Moon, will likely be sensitive. He or she may also have moods and a face that's as expressive as the Moon's phases.
Fittingly Tuesday is named after Tiw, the Nordic god of war, and Mars is clearly also an influence over that day (Martes means Tuesday in Spanish). Sure, active, assertive Mars isn't normally associated with being "full of grace," but a child born on Tuesday could cultivate natural elegance through their love of movement.
Mercury-ruled Wednesday marks the middle of the week and reflects adaptive Mercury's ability to be in the thick of things for the sheer mental excitement of it all. This brainy planet isn't often associated with woe, but perhaps too much stimulation can lead to worry—or maybe it gets at the planet's up-and-down mercurial nature.
Jupiter, the largest planet in our solar system, corresponds to Thursday. In astrology Jupiter oversees travel, good fortune and expansive thinking, so it makes sense that a child born on this day would have "far to go."
Friday shares a moniker with Venus, the goddess of love. Since Venus is indeed loving and giving, and a child born on that day could be as well. (One more reason to say "TGIF!")
Clearly, Saturday's namesake is Saturn, the planet of hard work and discipline. It stands to reason that kids born on that day would be more inclined to put their noses to the grindstone.
Although Sunday isn't the Sabbath for everyone, the bright, confident Sun fittingly describes a child who's bonny, blithe, good and happy!
Interestingly, not all days are equally popular for being born, at least according to data collected from the Center for Disease Control. According to the CDC's data statistics, Tuesday's children outnumber the rest, with 644,114 births between 2007 and 2012, followed by Thursday babies with 640,003 births. Wednesday's children come in third (635,951 births), trailed by Friday (626,435 births) and Monday (605,802 births). The weekend days had the lowest number of births, by far (422,436 on Saturday and 378,100 on Sunday).
So are we overrun with aggressive children of Mars and lacking in blissful Sunday babies? Not necessarily. The discrepancy may have less to do with astrology, and more to do with the fact that doctors prefer not to schedule C-sections on weekends.
These planetary descriptions aren't one size fits all. However, if your planetary day ruler is prominent in your chart, then it's likely that the day on which you were born does speak to your personality. Here's one way to know: Check your Personal Astrology Profile & Birth Chart, which will provide you with a colorful birth chart and pages of detailed explanation about all of your most influential planets.