Mercury Retrograde Dates Calculator
List every Mercury retrograde in any year from 1800 to 2050 with exact start and end times, zodiac degrees and shadow periods. Also Venus, Mars, Jupiter and Saturn.
Station times are when the geocentric longitude stops and turns, from JPL approximate orbital elements; checked against a full ephemeris for 1800–2050 they are within about half an hour for Mercury, an hour for Venus, three hours for Mars and six hours for Jupiter and Saturn, so a station near midnight can fall on the neighbouring date. The shadow begins when the planet first reaches the degree where it will end its retrograde, and ends when it passes the degree where the retrograde began.
Retrograde motion is an optical effect of Earth overtaking (or being overtaken by) another planet. Its meaning in astrology is tradition, not science.
| # | Shadow begins | Retrograde begins | At | Direct again | At | Shadow ends | Days |
|---|---|---|---|---|---|---|---|
| 1 | 2026-02-11 22:13 | 2026-02-26 06:51 | Pisces 22°34′ | 2026-03-20 19:42 | Pisces 8°30′ | 2026-04-09 11:39 | 22.5 |
| 2 | 2026-06-13 00:48 | 2026-06-29 17:48 | Cancer 26°15′ | 2026-07-23 22:54 | Cancer 16°19′ | 2026-08-07 03:38 | 24.2 |
| 3 | 2026-10-04 09:07 | 2026-10-24 07:17 | Scorpio 20°58′ | 2026-11-13 15:57 | Scorpio 5°02′ | 2026-11-30 06:13 | 20.4 |
A planet is “retrograde” when, seen from Earth, it seems to stop and drift backwards against the stars for a while before moving forward again. Mercury does this three or four times a year for about three weeks, which is why “Mercury retrograde” is a popular astrology topic. This calculator works out every retrograde period of Mercury, Venus, Mars, Jupiter or Saturn for any year from 1800 to 2050, with the exact turning times, the zodiac degrees and the shadow periods before and after.
How to use this tool
- Enter the year.
- Choose the planet (Mercury by default).
- Pick the time zone for the listed times.
- Read the periods in the table: shadow, retrograde start, direct station and end of shadow.
Formula
Station ⇔ dλ/dt = 0, where λ(t) is the planet's geocentric ecliptic longitude
The tool computes the longitude from JPL's approximate orbital elements for the planet and the Earth, scans the year day by day for a change in the sign of the daily motion, and refines each station by bisection to about a minute. The pre-shadow starts when the planet first reaches the longitude of its coming direct station; the post-shadow ends when it gets back to the longitude where the retrograde began.
Example
In 2025 Mercury turned retrograde on 15 March, 18 July and 9 November (UTC) and went direct again on 7 April, 11 August and 29 November — roughly three weeks each, about 67 days in all.
Frequently asked questions
Does a planet really move backwards?
No. All planets keep orbiting the Sun in the same direction. Retrograde motion is a line-of-sight effect as the faster Earth passes an outer planet, or a faster inner planet passes Earth.
How often is Mercury retrograde?
About every 116 days — three times in most years, occasionally four — for roughly 19 to 24 days each time.
Why do the times differ slightly from other calendars?
Near a station the planet barely moves, so a tiny difference in the computed position shifts the turning time. Mercury stations here are within about half an hour of a full ephemeris and Venus within an hour; for the slow outer planets the difference can reach a few hours (up to about six for Saturn), which can move a station that falls near midnight to the next or previous date. Calendars also differ by time zone.
Sources
The retrograde dates are astronomy; what astrology says about them is tradition with no scientific basis. Do not delay or make health, financial, legal or travel decisions because of a retrograde. How we check our calculators · Full disclaimer
Last updated:
Page address with these inputs: https://kakao.mobile/tools/mercury-retrograde-dates-calculator/
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kakaoCalc. (2026, November 8). Mercury Retrograde Dates Calculator. https://kakao.mobile/tools/mercury-retrograde-dates-calculator/
“Mercury Retrograde Dates Calculator.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/mercury-retrograde-dates-calculator/.
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