Decans
Sagittarius Decans: Which Sagittarius Are You?
Every Sagittarius aims past the horizon. The degree beside your Sun decides the first question you ask: what's there, when do we leave, or who's coming.

Someone says "let's go somewhere." First-decan Sagittarius asks "what's there?" Second-decan Sagittarius asks "when do we leave?" Third-decan Sagittarius asks "who's coming?"
All three of you are Sagittarius. You want the horizon the same way, and you'll get restless in the same town for the same reasons. But the degree the Sun sat at in your chart, that number just before the degree symbol on the Sun's line in any chart app, decides which question you ask first. The degree decides, not whichever description flatters you most.
The degree, not the date
Each zodiac sign spans 30 degrees. The decans cut that span into three 10-degree stretches: 0 through 9, 10 through 19, 20 through 29. Pull up your chart in whatever app you use and find the Sun's line. You'll see something like 13°22' Sagittarius. That 13 puts you in the second stretch, the Aries-flavored one. A 4 would put you in the first. A 25 lands you in the last.
If you were born in the first, middle, or last ten days of Sagittarius season, you can get a rough sense from the calendar. But the season starts on a slightly different day each year, and the Sun covers roughly one degree per day, so the birth date almost always settles it, and the degree in your chart settles it for certain. If you're sitting right on a boundary, at 9 or 19 degrees, the birth time tips the scales. Pull the degree and read the number.
The shading doesn't stop at the Sun. Mercury at 3 degrees Sagittarius thinks in big questions and wanders happily between them, like turning a topic over while making dinner and getting sidetracked by three tangents that are all fascinating. Mercury at 15 blurts the conclusion before the other person finishes asking. Mercury at 25 thinks like a teacher, turning a wild idea into a five-minute talk at the kitchen table.
Your Moon and your rising sign are a different story. The Moon changes signs so quickly it crosses a decan in under a day, and your rising degree can shift decans in about forty minutes on average. Without an accurate birth time, those decans are a guess. The Sun's degree is the one you can lock in from a date.
Mutable fire, sharpened by Aries and steadied by Leo
Sagittarius is mutable fire: a flame that wanders, always tilting toward the next idea, the next border, the next "but have you thought about it this way?" It doesn't sit still because it doesn't want to sit still. It's looking for meaning out past the edge of the familiar.
The decans run this fire through three different lenses. The first ten degrees are Sagittarius undiluted. The middle ten pick up Aries, a cardinal fire sign, whose urgency adds a go-now quality and a taste for being first into the unknown. The last ten pick up Leo, a fixed fire sign, whose warmth and loyalty add staying power and a wish to bring people along.
Aries takes Sagittarius's restless looking-over-there and turns it into legs already moving. Leo takes that same restlessness and says, "Wait, let's make it a group thing." Neither erases the Sagittarius. The sign stays primary. The decan is a shading, a second layer of color.
First decan (0 to 9 degrees): the seeker

You want to know why. Why people believe what they believe, what's on the other side of the next book or the next border, why the map has that blank shape in the middle. You'll chase one question across three books and two countries, and the canceled flight that strands you overnight becomes the best thing that could happen to the itinerary because now you've got forty-eight hours in a town that isn't on any guidebook.
This is Sagittarius aimed squarely at meaning. Your honesty comes out funny more often than sharp, and you'd rather ask a stranger at a dinner party about their whole life philosophy than make small talk about the weather. At work you need a horizon. A job with a larger purpose, or at least a larger map, keeps you from going feral under fluorescent lights. In love you need a fellow explorer who reads "I need a day alone" as a need for oxygen, not a rejection.
The 0-degree version of you just stumbled into Sagittarius territory, thrilled by the size of the world and not yet sure which way to point.
The blind spot is the near horizon. You know the history of three countries you've never visited. You found out last week that your roommate switched jobs, a month after it happened. Your postcards from abroad are legendary. She'd settle for one text asking how the new thing is going.
Second decan (10 to 19 degrees): gone before the plan is done
Aries takes Sagittarius's "I should go somewhere" and compresses it into "I am going somewhere, and I'll figure out the rest from the plane." You book the ticket during your lunch break. You tell your manager after, not before. You sign up for the mountain relay, then look up the elevation, then laugh and start training.
You're the boldest of the three decans. You'd go alone before you'd wait for a group to pick a trail. You go where nobody in your friend group has been, partly for the country and partly because nobody you know can say "oh, that's touristy." You're blunt, competitive in a way that's more fun than mean, and brave about burning a résumé page to start something new. In love you need someone who says yes now and asks questions later, and who doesn't need you to text back three times a day.
Your edge is the leap you can't undo. Words said hot, the apartment signed without checking the lease, the one-way ticket that turns into a one-way problem. What helps is a one-night rule before any move that can't be walked back. Sleep on it. The impulse will still be there, but the stupid, irreversible part of it will be gone.
Third decan (20 to 29 degrees): the guide who comes back
Leo gives you something rare for your sign: staying power. You still want the wide world, the big picture, the next question. But you want to lead people into it. You plan the group hike six years running, a different trail each year, and you give a short speech at the top. The regulars can recite the last two lines with you. You walk everyone up. You make sure nobody gets left at the switchback.
Over the years you commit to one field, one community, one home base, and you become the person people call when they want to understand it. You're warm, proud, generous, and you're a born mentor whether you call yourself one or not. In love you're more openly romantic than the reputation your sign carries, steadier, and you want to be genuinely admired by the person you chose. You say "I love you" like you mean the whole sentence, not just the first two words.
Someone at dinner pokes a hole in your take on a documentary you've built a whole opinion on, and you feel your jaw tighten. You notice it. You take it more personally than the documentary deserves. That's the growing edge: disagreement with your convictions lands like a slap. The conviction came from somewhere real, but the person poking at it isn't poking at you. You can hold the idea and let the argument be about the idea.
Six years into leading the same group up the same kind of mountain, you still give the speech. You still mean it.
After every trip
Whatever decan you landed in, every trip changes you in one small way you didn't plan for, and it sticks in you like a song.
You can't wait to tell someone. That's the part none of the decans skip. The wide world got bigger, and you have to pass it on, describe it, put it into words for someone who was there in spirit and will come next time. The horizon keeps moving. You'll chase it. And you'll want somebody beside you when you talk about what you saw.