What Mercury retrograde is
Mercury is the innermost planet. It circles the Sun in 88 days and overtakes the Earth about every 116, so three times in most years, and now and then four, it passes between us and the Sun. Around that pass, which astronomers call the inferior conjunction, Mercury appears from the Earth to slow down, stop, move backwards through the zodiac for about three weeks, stop again and then resume its usual eastward course.
Nothing changes in Mercury’s real orbit. The reversal is a matter of viewpoint, a trick of geometry. Mercury is the faster planet on the inside track: as it sweeps past the Earth, between us and the Sun, the place where we see it against the distant stars drifts backwards for a few weeks, although it never stops moving forward in its orbit. The moments when the apparent motion turns are called stations: the retrograde station, where Mercury goes from direct to retrograde, and the direct station, where it goes back to forward motion. The card at the top of this page works from them. It compares this moment with the stations and the shadow periods listed on this page, and answers in your time zone.
The shadow before and after
Mercury does not go backwards over new ground. It retraces a stretch of the zodiac, from the degree of the retrograde station back to the degree of the direct station. The shadow is the time Mercury spends on that stretch going forwards. The pre-shadow begins when Mercury first reaches the degree where it will later turn direct, and lasts until the retrograde station. The post-shadow begins at the direct station and ends when Mercury is back at the degree where it turned retrograde. Between the first moment and the last, Mercury crosses the same degrees three times: forward, backward and forward again, in about two months.
The October 2026 retrograde shows it. Mercury turns retrograde on 24 October 2026 at 20°58′ Scorpio and turns direct on 13 November 2026 at 5°02′ Scorpio. Its pre-shadow therefore begins on 4 October, when it first reaches 5°02′ Scorpio, and its post-shadow ends on 30 November, when it is back at 20°58′ Scorpio (dates in UTC). The exact times, and those of every other period in 2026 and 2027, are in the table on this page, in your own time zone.
In most modern readings the shadow is the gentler phase. The pre-shadow is the run-up, when the themes of the retrograde start to appear, and the post-shadow is the wind-down, when what was reopened is settled. Mercury moves at its slowest near the stations, so it lingers on the same few degrees of the zodiac for days, and astrologers watching a particular chart pay as much attention to those degrees as to the dates.
What it traditionally means
Mercury signifies speech, writing, papers, contracts, messages, short journeys, trade, siblings and young people, and in a chart it stands for the messenger, the clerk and the merchant. In traditional astrology retrograde motion is one of the accidental debilities, the conditions that weaken a planet by its situation rather than by its sign. William Lilly lists it among them in Christian Astrology (1647). A retrograde planet acts against its nature, late or by going back over something already done.
In horary astrology the chart is cast for the moment a question is asked, and a significator is the planet that stands for the person or the matter. A retrograde significator shows return, reversal or a change of mind: a lost thing that comes back, a plan that is revised, a decision taken twice. A related idea is refranation. If a planet that is applying to an aspect turns retrograde before the aspect is exact, the matter promised by that aspect does not perfect, and in Lilly’s examples someone backs out. The horary astrology guide explains significators, applying aspects and the other tests an astrologer makes before reading a chart.
Mercury being retrograde is therefore one condition among many. In horary it matters most when Mercury rules the question or sits in the chart in a prominent place, and it is read together with its sign, its house and its aspects. A retrograde Mercury does not by itself make a reading unfavourable.
What to do — and what not to
None of this requires superstition. The practical advice is old and sensible: slow down on what depends on Mercury’s matters. Read contracts, emails and bookings twice before you send or sign them. Keep backups of the files you rely on. Allow extra time for travel, and confirm the details of tickets, addresses and appointments. Expect some messages to be late, misread or lost, and say things plainly so that they survive.
The same weeks suit work that goes back. They are good for revising a draft, reviewing accounts, finishing what was left half done, repairing, returning, and getting back in touch with someone you lost touch with. If you can choose when to begin something new, many astrologers wait until Mercury is direct and out of the post-shadow, but a deadline is a deadline, and nobody needs to put their life on hold for three weeks. Nor is it a reason to be afraid of every email that arrives: a retrograde asks for care, not for avoidance.
Mercury retrograde in your own chart
The retrograde is the same for everybody, so what differs is where it falls in your own life. In a birth chart, Mercury goes back over the degrees between the two stations, and the house those degrees fall in tells you which area of life is revisited. Planets or angles of your chart near those degrees are touched three times, by the forward pass, the backward pass and the final pass. People with Mercury, Gemini or Virgo prominent in their chart often feel a retrograde more.
To find the house and the planets involved, cast your chart with the birth chart calculator. To see where Mercury and the other planets stand now, and which of them are retrograde at this minute, open today’s planetary positions, where every retrograde planet is marked with an R.
How AstroGPT reads a retrograde
AstroGPT is a horary astrologer in an app. You ask a question, it casts the chart for that minute and your place, and reads the answer from it. Mercury’s motion is part of that reading: if Mercury rules your question, its being retrograde says something about how the matter unfolds, whether it comes back, is reconsidered or is slow to arrive. You can ask follow-up questions on the same chart for about an hour.
It does not send alerts for the dates on this page, and it does not read your birth chart; the dates here are for you to plan by. Everything is offered for reflection and entertainment, and like any astrologer, AstroGPT can be wrong.
Have a question that can’t wait for Mercury to turn direct?
Ask AstroGPT: it casts the chart of the moment you ask and reads it by the traditional rules.