What is 삼재 (Samjae)?
Three years out of every twelve, decided by one thing — and the three are not a list to memorise. They fall out of where your animal sits on a circle.
The short answer
Samjae is a run of three consecutive years that comes round to everybody once every twelve, and the only thing that decides when yours arrives is the animal of the year you were born in. Nothing else goes into it: not your birth time, not your birth place, not your name, not a draw. The three years have names of their own — the entering year, the middle year, the leaving year — and they are usually handed to you as a table you look yourself up in. In Bokki it is one card in the deep report, and the card only appears while you are inside the window. It names the three calendar years and says which of the three you are standing in. If you are not inside the window, you will not see a card at all; we would rather show you nothing than a reassurance you did not ask for.
Why those three years, and not any other three
The table everyone copies looks arbitrary until you draw it. Put the twelve branches round a circle and your animal belongs to one of four trine groups, each group three animals sitting exactly a third of the circle apart: Monkey with Rat and Dragon, Snake with Rooster and Ox, Tiger with Horse and Dog, Pig with Rabbit and Goat. Every group has an opening branch — the one where its element is said to begin — and the first of your three Samjae years is the branch sitting directly opposite that opener, six places round, the relation called 충. Pig opens the Pig-Rabbit-Goat group, and Snake sits opposite Pig, so Snake years open that group's Samjae. We tested that reading against the table in our own code for all twelve animals and it held twelve times out of twelve, with no exception. The two years that follow are simply the next two branches along, which is why the three always add up to one whole season: 巳午未 is summer, 寅卯辰 spring, 申酉戌 autumn, 亥子丑 winter. So the three years are not a list. They are the season that begins opposite you.
Two things we found by counting
The first one surprised us less once we saw it, but it is worth saying plainly because Samjae is usually talked about as though it singles you out. It does not. We counted every year from 2020 to 2043 and asked how many of the twelve animals were inside the window each time. The answer was three, every single year, without one exception — a quarter of everybody, always. Counted the other way round, across the twelve years from 2020 to 2031 each of the twelve animals spent exactly three years inside. In 2026 it is Rabbit, Goat and Pig, and 2026 is the middle of their three; their window runs 2025, 2026, 2027. The second thing we did not expect at all. For four of the twelve animals the leaving year lands on their own zodiac year — Ox in 2021, Dragon in 2024, Goat in 2027, Dog in 2030 — so the year everybody congratulates them on is also the last year of their Samjae. The other eight never overlap that way, and we counted rather than guessed: four, not three, not five. It falls straight out of the geometry above. Those four are the closing branch of their own trine group, and the closing branch is also the last of the three seasonal years, so the two land on the same square.
Which birthday counts
This is where most disagreements between two sites come from, and it is worth being exact. Your animal does not change on 1 January and it does not change at the lunar new year either. It changes at 입춘, the start of spring in the solar-term calendar, which falls on 3 or 4 February. Someone born on 20 January 1987 is a Tiger, not a Rabbit — we checked the boundary directly, and 4 February 1987 still comes out Tiger while 5 February comes out Rabbit. That one day moves their Samjae from 2025 through 2027 all the way to 2028 through 2030. Bokki reads this from the solar terms, so nothing has to be converted by hand. One caveat we would rather write down than leave for you to find: the year we compare you against is the plain calendar year, so between 1 January and 입춘 the card is already naming the incoming year's phase. We measured the gap — 33 or 34 days a year across 2020 to 2030, an average of 33.7. In eight Januaries out of twelve that means the same three animals with the phase one step ahead of itself, and in the other four it means a different three animals altogether. It is on our list.
What we don't calculate
There is no number in Samjae anywhere in our code. What the calculation returns is whether you are inside, which of the three years it is, the three calendar years themselves and one sentence — no score, no percentage, no ranking, no probability, and nothing that could be turned into one. We do not tell you that something bad will happen, and every sentence the card can print ends the same way in all thirteen languages: that Samjae is not doom but a three-year window for going steady and tidying up. We do not calculate a personal severity, because the input is a single animal shared by a twelfth of the world and there is nothing personal left in it to grade. We do not read Samjae against your four pillars — that is a different calculation and a different card. And we do not decide anything about your health, your money or your relationships from it; if a page ever seems to, that is the page overreaching, not the rule.
Read next
See your own report — the Samjae card appears only while you are inside the window
What is 사주 (saju)? — the four pillars, from the beginning
What is 역마 (yeokma)? — the other rule built from the same 충 relation
What is 화개 (hwagae)? — the closing branch, the one four animals share with Samjae
What are the 24 solar terms? — where 입춘 comes from