Chinese New Year fell on 17 February in 2026 and will fall on 6 February in 2027. In 2028 it will be 26 January. The question people ask — why does Chinese New Year change dates? — has a precise answer, and it is not “because the calendar is lunar”. The traditional calendar is a lunisolar one: it counts months by the Moon and years by the Sun, and the arithmetic of fitting one into the other is what moves the holiday around inside a fixed window. Here is the rule as Taiwan’s official calendar office states it, the numbers behind it, and the dates for the next few years.
Months by the Moon, years by the Sun
The Central Weather Administration (中央氣象署), the agency that computes Taiwan’s official calendar every year, sorts the world’s calendars into three kinds. A solar calendar follows the Sun alone — the Gregorian calendar, which Taiwan uses for everything official, is one. A purely lunar calendar follows the Moon alone, twelve lunar months to a year, and drifts through the seasons; the Islamic calendar is the example the agency gives. And a lunisolar calendar, 陰陽合曆, does both: its months are lunar and its years are solar, and it uses an inserted “leap month” to keep them in step. That is the traditional Chinese calendar, called the 農曆, the farmers’ calendar, in Taiwan.
The two clocks do not divide evenly. Twelve lunar months add up to about 354 days; the solar year is 365.2422 days; the gap is eleven days a year. The agency’s own illustration of what would happen without correction: after sixteen years the first day of the lunar year would have slipped about 176 days behind the Sun, and you would be celebrating the Spring Festival in summer. So every two or three years an extra month is added — seven of them in every nineteen years — and the lunar year that contains one runs to thirteen months and 383 or 384 days.
The arithmetic, as the calendar office states it
19個回歸年 ＝ 365.2422日 × 19 ＝ 6939.6018日
12個朔望月 × 19 ＋ 7個朔望月 ＝ 29.53059日 × 235 ＝ 6939.6887日
“Nineteen tropical years = 365.2422 days × 19 = 6939.6018 days. Twelve synodic months × 19, plus seven synodic months = 29.53059 days × 235 = 6939.6887 days.”
中央氣象署數位科普網〈為何有閏月及閏年？〉 · Read the source
Nineteen solar years and 235 lunar months differ by about two hours. That coincidence — known in the West as the Metonic cycle, and in Chinese as 十九年七閏, “seven leap months in nineteen years” — is why the same lunar date returns to nearly the same Gregorian date every nineteen years. If you know when Chinese New Year fell in the year you were born, add nineteen and you will usually be within a day.
The rule that fixes the first day
None of that says which new moon starts the year. The calendar office’s rule has three parts, and the anchor is the winter solstice. First, the lunar month containing the solstice must be the eleventh month. Second, if there are thirteen lunar months between one eleventh month and the next, the first of them that contains no 中氣 — no “major solar term” — becomes the leap month, and takes the name of the month before it with 閏 in front. Third, the first month of the year, 正月, is counted from there.
In practice the agency states it more simply: since the reform of 104 BCE the first month has been the third month counting from the solstice, and that month normally contains the two solar terms “Beginning of Spring” (立春) and “Rain Water” (雨水). So New Year’s Day is, by custom, the new moon before Rain Water. Rain Water falls on 18 or 19 February every year; a lunar month is 29 or 30 days; therefore Chinese New Year can only fall between 21 January and about 20 February. It has done so every year in living memory, and the agency records exactly one modern exception to the “before Rain Water” formulation: 1985, when a leap month in 1984 produced two Beginnings of Spring and pushed the following new year past Rain Water — the previous such case being 1851.
The three-part rule for leap months
1.節氣冬至所在之農曆月須為農曆十一月。2.從農曆十一月開始到下一個農曆十一月之間，若有13個農曆月，取其中先出現不包含中氣的農曆月定為農曆閏月。3.閏月採用在其前1個農曆月的名稱前加「閏」字的方法表示。
“1. The lunar month containing the winter solstice must be the eleventh month. 2. If there are thirteen lunar months from one eleventh month to the next, the first of them that contains no major solar term is the leap month. 3. A leap month takes the name of the preceding month with the character 閏 prefixed.”
中央氣象署〈天文百問・曆法篇〉第九問「農曆置閏的原則為何」 · Read the source
The “major solar terms” are twelve of the twenty-four points that divide the Sun’s year: the solstices, the equinoxes, and eight others spaced between them. Because a lunar month (29.53 days) is slightly shorter than the gap between two major terms (30.44 days), a month with no major term in it turns up every two or three years, and that is the month that gets doubled. The agency’s example is 2020, when the month from 23 May to 20 June contained only a minor term and so became a second fourth month, 閏四月.
The dates, 2024 to 2031
These are from the Hong Kong Observatory’s published Gregorian–lunar tables, which agree with Taiwan’s official calendar; both are computed from the same astronomy. Years with a leap month are marked, because they are the years the following New Year jumps latest.
| Year | Chinese New Year | Year name | Animal | Leap month |
|---|---|---|---|---|
| 2024 | 10 February | 甲辰 | Dragon | — |
| 2025 | 29 January | 乙巳 | Snake | Leap sixth month; 384-day year |
| 2026 | 17 February | 丙午 | Horse | — |
| 2027 | 6 February | 丁未 | Goat | — |
| 2028 | 26 January | 戊申 | Monkey | Leap fifth month |
| 2029 | 13 February | 己酉 | Rooster | — |
| 2030 | 3 February | 庚戌 | Dog | — |
| 2031 | 23 January | 辛亥 | Pig | Leap third month |
Two things in the table are worth noticing. The animal changes on New Year’s Day, not on 1 January, so a child born in the first week of February 2027 belongs to the Horse year that is ending, not the Goat year that has not begun; and the sixty-year name in the third column is the older and more precise label, of which the animal is a popular shorthand. Taiwan’s calendar office publishes the same information in its annual calendar tables; its 2025 sheet, for instance, is headed with the note that the lunar year 乙巳 has a leap sixth month and 384 days.
Why the holiday is not simply fixed
It could have been. Japan moved its New Year to 1 January in 1873 and never looked back. The reason the Chinese-speaking world did not is that the lunar calendar is not decorative: it still schedules the festivals. Ghost Month is the seventh lunar month, Mid-Autumn is the fifteenth of the eighth, Qingming is a solar term, and the temple calendar runs on the lunar dates of the gods’ birthdays. Fix New Year to the Gregorian calendar and everything else would have to be fixed or would float free of it. In Taiwan, where Ghost Month changes what people schedule and Mid-Autumn empties the supermarkets of charcoal, that was never going to happen. The lunar calendar is printed in every diary next to the Gregorian one, and most people simply know both.
There is also a quieter point in the calendar office’s page. The reason the year has been counted from this particular month “since the first year of Taichu” — 104 BCE, under the Han emperor Wu — is that the choice of first month was political, made by rulers to “unify the political pace and govern their subjects”. Earlier dynasties had started the year from other months. The solstice-anchored astronomy is ancient and impersonal; the decision that this new moon is the New Year is a decree that has simply held for more than two thousand years.
Once you know when the new year falls, the other question is what you are and are not supposed to do when it arrives. Chinese New Year taboos traces the rules back to their sources and asks what each one is protecting.
The origin story usually attached to the festival — a beast that fears the colour red — turns out to have no early source at all, while Taiwan kept an older tale in which the island itself was about to sink. See the Nian monster did not invent Chinese New Year.
FAQ
Why does Chinese New Year change dates every year?
Because the traditional calendar counts months by the Moon and years by the Sun. Twelve lunar months are about eleven days short of a solar year, so New Year’s Day moves about eleven days earlier each year until a leap month is inserted, after which it jumps roughly nineteen days later. Seven leap months are added every nineteen years.
What is the earliest and latest date it can fall on?
Between 21 January and about 20 February. By custom the first day of the year is the new moon before the solar term Rain Water (18–19 February), and a lunar month is 29 or 30 days long, which sets the window.
Who decides the date?
Nobody decides it year by year; it follows from the rule and from astronomy. In Taiwan the Central Weather Administration computes and publishes the official calendar; in Hong Kong the Observatory does; the results agree because the rule is the same.
When is Chinese New Year 2027?
Saturday, 6 February 2027, beginning the year 丁未, the year of the Goat.
The Double Ninth moves against the solar calendar for the same reason, landing on 18 October in 2026. See the Double Ninth in Taiwan.
The fifth of the fifth wanders across the Gregorian calendar for exactly the reasons set out above — and its origin story turns out to be a later addition to a date that was already being kept: was the Dragon Boat Festival really created for Qu Yuan?
Sources
- 中央氣象署數位科普網〈為何有閏月及閏年？〉 — pweb.cwa.gov.tw：陽曆／陰曆／陰陽合曆三分法；354 日與 365.2422 日之差；十九年七閏之算式（accessed 2 Sep 2026）
- 中央氣象署〈天文百問・曆法篇〉 — cwa.gov.tw：第九問「農曆置閏的原則為何」三原則與 2020 年閏四月之例；第十一問「歲首」：太初元年（西元前 104 年）建寅、取雨水前朔日為正朔、1985 年與 1851 年之例外（accessed 2 Sep 2026）
- 中央氣象署〈中華民國 114 年日曆資料表〉 — cwa.gov.tw：「農曆歲次乙巳年閏 6 月計 384 日」（accessed 2 Sep 2026）
- 香港天文台〈公曆與農曆對照表〉純文字版 2024–2031 — hko.gov.hk：各年正月初一、立春、雨水及閏月日期（accessed 2 Sep 2026）
