How to use it
- Type the year, or leave the box empty to see this year.
- Read the table: each row is one retrograde, from the station where the planet turns backward to the station where it turns direct again.
- Look at the timeline to see in which months several planets are retrograde at once.
- Tick Show times in UTC if you want Universal Time.
How the periods are found
A planet is retrograde while its apparent longitude, seen from the Earth, decreases. The stations are the turning points, where the apparent speed is zero. For each planet the calculator samples the speed every day, finds each change of sign and narrows it down to one minute.
Mercury and Venus, which are closer to the Sun, turn retrograde about once every few months. The outer planets turn retrograde once a year or less, and stay retrograde for months: Pluto for about five months.
speed = (longitude at t + 6 h − longitude at t − 6 h) ÷ 0.5 day
A station is the moment the speed changes sign.Reading the timeline
Each bar is one month. Its stacked parts are the days each planet spends retrograde in that month, so a tall bar means several planets are retrograde together. A period that crosses a month boundary is split between the two months.
What this calendar does not include
- Meanings. Astrology assigns meanings to retrograde periods; this calendar gives the astronomical dates and signs only.
- The Sun and the Moon, which are never retrograde.
- Shadow periods. Those are described for Mercury on its own page.
Worked example: Jupiter across New Year 2025 to 2026
Jupiter turned retrograde on 11 November 2025 at 16:45 UT, at 25° 09′ Cancer, and turned direct on 11 March 2026 at 03:26 UT, at 15° 05′ Cancer. The period is 119 days long, and it falls in two calendar years.
In the 2026 calendar it is listed as the first Jupiter row, because it ends in 2026. The timeline shows 31 days of Jupiter in January 2026, 28 in February and about 10 in March.
Frequently asked questions
Which planets go retrograde?
All of them except the Sun and the Moon. Mercury and Venus are retrograde most often, while Pluto has a long retrograde of about five months once a year.
Why does the calendar show dates from the previous year?
A retrograde that starts in one year and ends in the next is listed for both years, so the table shows every period that touches the year you chose.
Are the dates exact?
The stations are found to the nearest minute from the planets' positions. The Mercury positions agree with the JPL Horizons ephemeris to a few thousandths of a degree.
Can I use the calendar for another year than the current one?
Yes. Type any year from 1900 to 2100 in the Year box and the table and timeline are drawn again for that year.
Sources
- JPL Horizons, NASA's ephemeris system, used to check the positions
- astronomy-engine, the open-source astronomy library (MIT) that computes the positions
Figures and text last checked on Tuesday, November 10, 2026.