Dates and Days

Moon sign calendar

Which sign the Moon is in, and what the tradition calls that day

Root, leaf, flower and fruit days, computed from the Moon’s sidereal position rather than copied from a printed calendar — so every changeover comes with the exact instant it happens.

Day type— Moon in— Element— Changes at— Next fruit day—
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The month at a glance

Changeovers — every sign change this month, in UTC
DateTime (UTC)Moon entersDay type

What the four types are

The scheme is old and simple. The twelve signs carry the four classical elements three apiece, and each element is associated with a part of a plant: the fire signs with fruit, the earth signs with root, the air signs with flower, the water signs with leaf. As the Moon moves through the sky it spends about two and a third days in each sign, so the four types cycle roughly every nine or ten days.

The correspondence between element and plant part is about two thousand years old and is published identically by everyone who uses it. What is more recent — and much more contested — is the twentieth-century proposal that the cycle governs how plants actually grow, and, in the version that reached the wine trade, how a bottle shows on the day you open it.

The wine reading

Some drinkers and a number of tasting rooms follow the same four types for opening bottles rather than sowing seed: fruit and flower days are held to be the days a wine shows best, root and leaf days the days to leave it alone. It is a pleasant piece of shared ritual, it gives a table something to argue about, and it costs nothing to try.

There is no good evidence it is true. The underlying trials were about sowing rather than tasting, they are contested, and the substantial independent study of the question found effects from other lunar rhythms but not this one. Nobody has replicated a controlled tasting result either way. This page tells you what day the tradition says it is; it does not tell you what is in your glass, and it would be inventing something to pretend otherwise.

Why this will not match your printed calendar

Two reasons, and both are deliberate. The first is that this divides the sky into twelve equal thirty-degree signs, while the published calendars use the observed constellations, which are wildly unequal — Virgo covers more than forty degrees of the ecliptic and Scorpius about seven. The second is that this computes the sequence rather than reproducing anyone’s: a printed calendar is somebody’s work, and copying its day sequence would be taking it. The visible disagreement is the consequence of not doing that.

It also means the zodiac has to be named to be checkable, which most pages skip. This one uses the sidereal zodiac with the Fagan-Bradley ayanamsa, currently a little over twenty-five degrees from the tropical zodiac your horoscope uses. The method page gives the arithmetic.

Changeovers, not days

Because a sign lasts about two and a third days, a changeover falls inside a calendar day more often than not. A calendar that prints one type per day has quietly chosen either the type at midnight or the one covering the most hours, and has not said which. This page shows both types on a split day and lists every changeover instant in the table above, so you can see whether the bottle you are opening at eight in the evening is on the same side of the line as breakfast was.

Questions

Which zodiac is this — the one in my newspaper horoscope?
No. This uses the sidereal zodiac, which measures position against the stars, and newspaper horoscopes use the tropical zodiac, which measures against the equinox. The two drifted apart because the equinox itself moves, by about one degree every seventy-two years, and they are now roughly twenty-five degrees apart — most of a whole sign. The gap is called the ayanamsa, and the value used here is the Fagan-Bradley one, twenty-four degrees two minutes and thirty-one seconds at 1950, carried forward by the standard precession formula. Naming the convention matters: a page that prints a sign without saying which zodiac it used has told you nothing you can check.
Why does this not match the printed calendar I already own?
Because it is computed rather than copied, and the two use different sign boundaries. This page divides the sky into twelve equal thirty-degree signs. The published biodynamic calendars use the observed constellations instead, which are nothing like equal — Virgo sprawls across more than forty degrees of the ecliptic and Scorpius across about seven — so the day a type changes will often differ by a day or so, and occasionally more. Neither is wrong; they are answers to slightly different questions. Reproducing a published calendar's own sequence would be copying somebody's work, so this does not do that, and the disagreement is the visible consequence of not doing it.
Does the day-type actually change how a wine tastes?
There is no good evidence that it does. The idea comes from decades of sowing trials rather than tasting ones; the trials themselves are contested, and the one substantial independent study over three years found effects from other lunar rhythms but specifically not from this one. No replicated body of controlled work supports the tasting claim either way. This page tells you what the tradition says the day is, which is a fact about the tradition, and makes no claim at all about what is in your glass. Plenty of people find it a pleasant way to choose a bottle, and that is reason enough for it to exist.
What happens when the Moon changes sign in the middle of the day?
The day gets two types, and both are shown with the time the changeover happens, in UTC. This is not a rare edge case — the Moon spends only about two and a third days in each sign, so a changeover falls inside a calendar day more often than not. A calendar that assigns one type per day has silently picked either the type at midnight or the type that covers most hours, and has not told you which. The table under the grid lists every changeover in the month with its exact instant.
Where does root, leaf, flower and fruit come from?
From the four classical elements, by way of the zodiac triplicities — a correspondence that is roughly two thousand years old and appears in essentially every source on the subject. The fire signs Aries, Leo and Sagittarius carry fruit; the earth signs Taurus, Virgo and Capricorn carry root; the air signs Gemini, Libra and Aquarius carry flower; and the water signs Cancer, Scorpio and Pisces carry leaf. The twentieth-century contribution was not the mapping but the proposal that it governs how plants grow. The mapping itself is old, public and used identically by everyone who uses it.