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Mercury Retrograde Calculator (Dates, Signs & Shadow Periods — also Venus & Mars)

Q: When is Mercury retrograde in 2026?

Three times: February 26 – March 20 (Pisces), June 29 – July 23 (Cancer) and October 24 – November 13 (Scorpio), in UTC. Your local dates can differ by a day near midnight; set your time zone.

Q: Does Mercury actually move backwards?

No. Mercury always orbits the Sun in the same direction. Because it laps Earth every 116 days, our line of sight to it swings backwards against the background stars for about three weeks — like a slower car seeming to drift backwards when you overtake it.

Q: What are the shadow periods?

The pre-shadow is when Mercury first crosses the stretch of sky it will later retrace; the post-shadow is when it finally moves past the point where the retrograde began. Astrologers treat them as warm-up and cool-down periods.

Q: Is Mercury retrograde bad luck?

There is no scientific evidence that Mercury's apparent motion affects communication, technology or relationships. The calculation of the dates is real astronomy; the interpretation is folklore and entertainment.

When is Mercury retrograde? Exact station retrograde and station direct dates and times for any year from 1900 to 2050, the zodiac signs involved, the pre- and post-shadow periods and days retrograde — also for Venus and Mars.

Year

Planet

Time zone (UTC offset)

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How it works

Geocentric longitude λ(t) of the planet from JPL Keplerian elements (Earth and planet orbits, light time, precession, aberration, nutation) · station = moment the daily motion dλ/dt changes sign (found by bisection to < 1 minute) · retrograde = from station retrograde to station direct · pre-shadow begins when the planet first reaches the longitude of the later station direct; post-shadow ends when it passes the longitude of the station retrograde again

A planet is "retrograde" when, seen from Earth, it appears to move backwards (westward) through the zodiac. It is an optical effect of Earth overtaking an outer planet, or of an inner planet like Mercury catching up with and passing Earth on the inside track. Mercury does it three or four times a year for about three weeks, Venus every 19 months for about six weeks and Mars every 26 months for about ten weeks. The station dates here come from NASA JPL orbital elements and agree with published ephemerides to within minutes to a few hours. Popular astrology blames Mercury retrograde for miscommunication and broken gadgets; there is no evidence for that.

Worked example

In 2026 Mercury is retrograde three times (UTC): from February 26, 2026 (06:51) to March 20, 2026 (19:41) in Pisces, from June 29 to July 23 in Cancer, and from October 24 to November 13 in Scorpio — about 67.1 days, 18.4% of the year. The first period's pre-shadow begins on February 11, 2026 and its post-shadow ends on April 9, 2026.

Sources: NASA JPL — Approximate positions of the planets · NASA Space Place — What is retrograde motion?

Frequently asked questions

When is Mercury retrograde in 2026?

Three times: February 26 – March 20 (Pisces), June 29 – July 23 (Cancer) and October 24 – November 13 (Scorpio), in UTC. Your local dates can differ by a day near midnight; set your time zone.

Does Mercury actually move backwards?

No. Mercury always orbits the Sun in the same direction. Because it laps Earth every 116 days, our line of sight to it swings backwards against the background stars for about three weeks — like a slower car seeming to drift backwards when you overtake it.

What are the shadow periods?

The pre-shadow is when Mercury first crosses the stretch of sky it will later retrace; the post-shadow is when it finally moves past the point where the retrograde began. Astrologers treat them as warm-up and cool-down periods.

Is Mercury retrograde bad luck?

There is no scientific evidence that Mercury's apparent motion affects communication, technology or relationships. The calculation of the dates is real astronomy; the interpretation is folklore and entertainment.

Related calculators

Venus Sign Calculator

Find your Venus sign — and your Mars and Mercury signs — from your birth date and time, with the exact degree, element, whether the planet was retrograde, when it entered and left that sign, and a mini chart of your personal planets.

Moon Sign Calculator

Find your Moon sign from your birth date and time with an astronomical lunar position (Meeus series), the degree, element and Moon phase at birth, whether the Moon changed sign that day, and when it enters each of the 12 signs.

Rising Sign Calculator

Find your rising sign (ascendant) from your birth date, exact birth time, time zone and birthplace coordinates, computed astronomically from sidereal time — plus your midheaven, Sun and Moon signs and when each of the 12 signs rises.

Synodic Period Calculator (Planet Oppositions & Launch Windows)

Calculate the synodic period between two orbiting bodies from their sidereal periods — how often Mars reaches opposition, Venus its inferior conjunction, or two moons line up — plus the next alignment date and a table for every planet relative to Earth.

Moon Phase Calculator

Find the Moon’s phase for any date and time in your time zone: the illuminated percentage, the Moon’s age, which side is lit, its distance and zodiac sign, the next new, quarter and full moons, and a day-by-day moon calendar for the month — using Meeus’s astronomical algorithms.

For entertainment and cultural interest only. Astrology and numerology have no scientifically demonstrated power to describe personality or predict events.