There are four periods between now and December 2027, and each one lasts between twenty and twenty-four days. The times are Brasília time, and they come from the same ephemeris this site uses to build a chart, not from a memorised table.

In Scorpio, from October 24, 2026, at 04:11, to November 13, 2026, at 12:55, with the shadow from October 4 to November 30; starting in Pisces and ending in Aquarius, from February 9, 2027, at 14:35, to March 3, 2027, at 09:38, with the shadow from January 25 to March 23; starting in Cancer and ending in Gemini, from June 10, 2027, at 15:20, to July 4, 2027, at 16:39, with the shadow from May 26 to July 19; and starting in Scorpio and ending in Libra, from October 7, 2027, at 11:36, to October 28, 2027, at 11:13, with the shadow from September 17 to November 13.

Look at the shadow of each one. It is the part almost no site publishes, and the one that explains why the feeling of “it has already started” usually arrives before the date.

Before stopping, Mercury covers, moving forwards, the same piece of sky he will cover again backwards. That outward stretch is called the shadow, and it opens about two weeks before the date everybody publishes.

The calculation is simple to state and tedious to do, which is why it disappears from the sites: the shadow opens on the day Mercury crosses the degree where he will stop going back, the degree of the direct station, and it closes on the day he returns to the degree where the retrograde began. It is not a fixed span of days: it is a search, and it changes from period to period.

In practice the shadow is what names what a person was already feeling. The matter that will be reviewed usually shows up there, on the way out, and comes back in the middle of the retrograde to be redone. Anyone looking only at the two middle dates thinks the period started out of nowhere.

Before the list, the figure that puts it all in scale: Mercury is retrograde 19% of the time, and that is measured in what a retrograde planet is. One day in every five of your life was lived that way, including the best ones. The period is not an interruption of normality, it is a fifth of it.

What tradition associates with the phase is review, and the prefix organises the list: revisit, revise, resume, reconnect, redo. It is a window in which attention pays off more on what already exists than on what is starting.

Three concrete uses, and none of them is stopping:

• Finish what was left half-done. The stalled project, the unfinished conversation, the text still in draft. The phase favours whoever comes back.
• Reread before you sign. Not because the sky is going to sabotage the contract, but because rereading is always good, and these weeks give you the excuse you were missing.
• Let the dust settle before you announce. An arrangement made during the phase tends to be renegotiated later. It is not bad luck: it is that the matter was still moving.

And there is the effect nobody measures and everybody feels: knowing that Mercury is retrograde changes your behaviour. A forewarned person checks the address, saves the file twice, rereads the message before sending it. A good part of what gets attributed to the sky in those weeks is attention moving, and that is not a small thing, it is just a different thing.

Twenty-two days, three times a year, is two months of life a year. Anyone who organises their diary around Mercury loses more time than any lost message would cost.

Do not postpone anything with a deadline: a proposal, an enrolment, a treatment, a move already decided. Do not cancel a trip you have paid for. And do not put off a conversation that needs having, the phase is good precisely for picking up an old subject.

What is worth postponing, when you can, is the launch: the opening night, the announcement, the new site, the hire. Not because it will go wrong, but because all of that tends to need adjusting afterwards, and the phase multiplies the adjusting.

A retrograde planet in the birth chart is not a transit: it is a fixed trait, for life. Someone born with Mercury retrograde does not spend life stuck in the period, they have their own way of thinking, more from the inside out, which usually shows up as thinking first and speaking afterwards.

It is common: with the real proportions, most people are born with at least one retrograde planet. The text that describes this in detail is what a retrograde planet is, and it carries the proportions for every planet, from Mercury to Pluto.

And the questions that come up most on this subject, with the short answer: