Quick answer: An ephemeris is a table giving each planet's zodiac position for a series of dates, usually at 00:00 Universal Time. Each row is a date; each column is a planet; each cell is a sign, a degree and a minute, with an R when that planet is retrograde. Read down a column to see a planet move; read across a row to see the sky on one day. Our tables for 2025 to 2027 give twelve bodies a day, and everything on this site is computed from the same Swiss Ephemeris data.
For two thousand years, astrology was a table-reading discipline. Before software, an astrologer's most valuable possession was a book of planetary positions, and casting a chart meant looking up numbers and doing arithmetic. The software has removed the arithmetic, which is a real gain, but it has also removed the habit of looking, which is a real loss. An astrologer who can read an ephemeris can check any claim about the sky, including ours, in about fifteen seconds.
This is a column-by-column walkthrough, using our own tables as the example.
What an Ephemeris Actually Is
The word comes from the Greek for "daily", and that is all it means: a daily record. A modern astrological ephemeris gives, for each date in a range, the ecliptic longitude of the Sun, the Moon and the planets, expressed in the zodiac's own units.
Two conventions are worth knowing before you look at a single number.
The positions are given for a specific moment of each day, not for the whole day. Almost every ephemeris uses 00:00 Universal Time, which is midnight at Greenwich. Ours does too. This matters most for the Moon, which travels about thirteen degrees a day: if you read the Moon's position for your birthday off a table and your birth was at six in the evening, you are off by roughly seven degrees, which is easily a different sign near a boundary. For anything precise, cast the chart; the table is for seeing the shape of the sky, not for replacing a calculation.
They are geocentric and tropical. Geocentric means positions as seen from the centre of the Earth, which is the frame Western astrology has always used. Tropical means the zodiac is measured from the spring equinox rather than from the constellations, so 00 degrees Aries is the equinox point by definition.
Reading a Cell
A single cell is a position in the zodiac, and it has three parts:
Leo 13 degrees 25 minutes
The sign is one of the twelve thirty-degree divisions. The degree is how far into that sign the body has travelled, from 0 to 29. The minute is a sixtieth of a degree, the same unit as in geography. Some ephemerides add seconds; ours stops at the minute, which is finer than any interpretation needs.
The full circle runs Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, and then back to Aries. A body at 29 degrees 59 minutes of Leo is one minute from entering Virgo. That moment of crossing is called an ingress, and it is one of the most useful things a table shows you at a glance.
The R, and What It Does Not Mean
An R beside a position means the planet is retrograde: from our point of view on a moving Earth, it appears to be travelling backward through the zodiac. Read down a retrograde column and the degrees decrease instead of increasing.
Nothing in space is reversing. Retrograde motion is an effect of two planets on different orbits passing each other, in the same way a slower train appears to slide backward when your own train overtakes it. The planet continues forward around the Sun throughout. Our guide to retrograde planets covers the astronomy and the traditional reading in more depth.
The moments either side of a retrograde period are worth noticing in a table, because they are where a planet's daily movement drops to almost nothing before changing direction. Those are the stations, and traditional astrology treats a stationary planet as unusually emphatic, on the reasoning that a planet standing still is a planet lingering.
Reading Down: One Planet Over Time
Pick a column and read downward, and you are watching one body move.
The Sun is the metronome. It advances close to one degree a day, so it changes sign about every thirty days. In 2026 our own tables put those crossings between the 19th and the 24th. If a table shows the Sun moving noticeably faster or slower than a degree a day, something is wrong with the table.
The Moon is the sprinter, covering roughly twelve to fifteen degrees a day and changing sign every two and a half days or so. It is the only body whose position is genuinely unusable at day resolution.
The outer planets are the slow hands of the clock. Jupiter takes about a year per sign, Saturn about two and a half, Uranus about seven, Neptune about fourteen, Pluto between twelve and thirty depending on where in its eccentric orbit it is. Read a Saturn column down a whole year and it may not leave the sign it started in.
Reading down is how you find the answer to the most common practical question in astrology: when does this planet enter that sign, and when does it turn around. You do not need a calculation. You need to scan for where the sign name changes, or where the R appears.
Reading Across: One Day's Sky
Read a single row and you have the whole sky on that date, which is the raw material of a transit reading. Two bodies at the same degree of the same sign are conjunct. Two at the same degree of opposite signs are opposed. Signs four apart at similar degrees make a trine, three apart a square, two apart a sextile.
That is the entire aspect toolkit, and once you can see it in a row you can read the sky's mood off a table without software. Our guide to aspects covers what each one means; the ephemeris is where you spot them.
Reading across is also how you check a claim. If an article says two planets meet on a particular date, the row for that date either shows them at the same degree or it does not.
What Our Own Tables Give
Our ephemeris pages publish 00:00 UT positions for 2025, 2026 and 2027, one page per year and one per complete month, covering twelve bodies: the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, the true node and Chiron. Each row carries the Moon's phase as well.
A few notes on what those choices mean:
- The node given is the true node, which oscillates, rather than the smoothed mean node that only moves backward. The difference is usually small but it can move an ingress date by a few days, which is why we say which one we publish.
- Chiron and Pluto are modern additions. Classical astrology worked with the seven visible bodies, and our written interpretations weight them accordingly, but the table includes them because readers expect them and a table should not decide what you are allowed to look at.
- Only complete months are published as month pages, so a table you can reach is never a table with days missing from it.
Four Things to Try
If you want the skill rather than the theory, these four exercises give it to you in about twenty minutes.
- Find your own Sun degree. Look up your birth date and read the Sun's cell. If you were born within a day of a sign change, you have just learned why "cusp" arguments happen.
- Follow the Moon for a week. Read seven consecutive rows and watch it cross a sign boundary. Then check when it is void of course, which is the stretch after its last aspect before that crossing.
- Find a station. Scan a planet's column for where the R appears or disappears, then look at the two days either side and see how little it moved.
- Check a headline. Take any dated claim about the sky from anywhere, including this site, and look up the row. This is the habit worth building.
Frequently Asked Questions
What time of day do ephemeris positions refer to?
Almost always 00:00 Universal Time, midnight at Greenwich, and that is what our tables use. It matters most for the Moon, which moves about thirteen degrees a day, so a position read from a table can be several degrees away from where the Moon was at a particular hour. For an exact position at a given moment, cast a chart rather than reading a daily table.
What does the R next to a planet mean in an ephemeris?
It means the planet is retrograde: from Earth it appears to move backward through the zodiac, so its degrees decrease from row to row. Nothing reverses in space. It is an effect of two planets on different orbits passing one another, and the planet keeps orbiting the Sun forward the whole time.
How do I find when a planet changes sign?
Read down that planet's column and look for the row where the sign name changes. The crossing is called an ingress. For fast bodies like the Moon this happens every two or three days; for Saturn it may not happen at all within a year of rows.
Is the true node different from the mean node?
Yes. The mean node is a smoothed average that only ever moves backward, so it crosses a sign boundary once. The true node is the actual intersection of the Moon's orbit with the ecliptic at that moment, and it oscillates, so it can cross a boundary, slip back and cross again. Our tables publish the true node, which is why an ingress date here can differ by a few days from a source that uses the mean.
