Moon Sign Body Calendar

The calendar lists, one month at a time, each moment at which the Moon enters a new sign of the zodiac, with the sign entered and the region of the body that the old lists gave that sign. Each row is one entry: a date, a time in Coordinated Universal Time to the second, a sign and a region. The rows of a month run in order, and the first row carries the sign the Moon was already in when the month opened, so that no day is left without a sign against it.

The region column is the historical part. It repeats, row by row, the assignment that Manilius put into Latin verse in the first century and that the almanacs of early modern England printed beside their calendars: the head and face to Aries at the top of a standing figure, the neck and throat to Taurus below it, and so on down to the feet, which the lists gave to Pisces. The column changes nothing in that list and adds nothing to it. It is there so that a reader can see what an almanac page of the seventeenth century paired with each day, and nothing on the page describes a reader or anyone else.

The rest of the page explains the three things the table combines: the astronomy that makes the Moon change sign every couple of days, the computation that fixes each change to the second and the clock it is shown in, and the history of the region list and of the rule the almanacs printed beside it. The rule is told in the past tense, because on this site that is all it is.

The table below holds one month. Each row gives the day and the time, in UTC, at which the Moon’s longitude reached the first degree of a sign, the sign it entered, and the region the old lists gave that sign. The first row of every month is the sign carried in from the month before, printed without a time, since the Moon entered it before the month began. The remaining rows are the entries that fall inside the month, in the order they happen.

Thirteen or fourteen rows is the usual run. The Moon passes through every sign about once a month, taking a little over two days for each, so a month of thirty or thirty-one days holds twelve or thirteen entries and the carried-in row makes one more. February holds fewer. The spacing between rows is uneven in the way the next section explains, and the unevenness is in the sky and the data, not in the table.

The sign column links each sign to its page on this site. The region column is plain text and links nowhere, because the regions are a historical list and not a set of pages. The Zodiac Man guide prints the list in full with the four sources that give it and explains where the four differ. The controls above the table step between months and between the years the site keeps on file; nothing is recomputed in the browser, which only chooses which rows to show and in which clock.

The twelve signs of the tropical zodiac are twelve equal arcs of the ecliptic, the circle the Sun appears to trace through the sky over a year, measured from the point the Sun occupies at the March equinox. Anything that moves along or near that circle passes through the twelve arcs in turn. The Sun takes a year to go round, so it spends about a month in each sign. The Moon goes round the whole circle in a little over twenty-seven days, so it spends a twelfth of that in each sign, which comes to a little over two and a quarter days. The usual round figure of two and a half days is the same fact stated loosely.

The twenty-seven days is the time the Moon takes to return to the same place against the stars, which astronomers call the sidereal month. It is shorter than the month from one new Moon to the next, which runs about twenty-nine and a half days, because the Sun moves on through the zodiac while the Moon goes round, and the Moon needs two more days to catch up with it. The sign changes follow the shorter period, since a sign is a fixed arc of the ecliptic and the Moon’s place in it has nothing to do with its phase.

The Moon’s orbit is not a circle but an ellipse, so its speed along the ecliptic rises and falls through each month. Near perigee, its closest approach to the Earth, it covers a sign in a little under two days. Near apogee, its farthest point, it takes two and a half days or a little more. The Sun’s pull adds a smaller rhythm on top of that one, so the rows of the table run in short stays and long stays by turns.

Because the sidereal month is shorter than any calendar month, the Moon goes round the zodiac a little more than thirteen times in a year, so the count of entries into any one sign comes to thirteen or fourteen. The second data block on this page reports that count for the year the table shows.

Each row’s time is the instant at which the Moon’s apparent geocentric longitude, its position along the ecliptic as seen from the center of the Earth, crossed the boundary of a sign. The boundaries lie at every thirtieth degree from the equinox point, so an entry into Taurus is the moment the Moon’s longitude reaches the thirtieth degree, and so on round the circle. A script steps forward from the start of each year, finds each crossing in turn with the site’s astronomical routines, and rounds the result to the nearest second. The output is one file per year, committed with the site, which the page reads when it loads.

Apparent means the position as it would be seen, after allowing for the time light takes to arrive and the small shifts due to the Earth’s own motion. Geocentric means from the Earth’s center rather than from any place on its surface, so the table is the same for every reader wherever they are. Both are the choices the site’s natal charts make, so a chart and this table agree on the Moon’s sign to the second, and the methodology page describes the computation in more detail.

The times are stored in Coordinated Universal Time and the table shows them in UTC first, because UTC is one clock for every reader and never jumps for daylight saving. The page then offers the reader’s own time zone, taken from the browser, as a second view, and the switch between the two is a conversion of the same instant rather than a new computation. An entry late in the evening by UTC falls on the next calendar day in a zone east of Greenwich, so the date against an entry can differ between the two views while the instant does not.

The second is the precision of the stored value and not a claim about the sky. The boundary the Moon crosses is a definition rather than a mark among the stars, so a crossing time is exact for the tropical zodiac this site uses and would fall elsewhere under a sidereal zodiac, as the question on the constellations below explains.

The data block below counts the sign entries in the year the table is showing. For 2026 the file holds 160 entries, and the Moon opened the year in Gemini, the sign it carried in from the last days of the year before. The count is the number of rows the twelve month tables hold between them, less the twelve carried-in rows at the top of each month, since those repeat a sign the Moon had already entered.

The number sits close to thirteen times twelve, because the Moon goes round the zodiac a little more than thirteen times in a year, and it lands one above or one below that from year to year according to where the year’s end falls in the Moon’s circuit. No sign is ever skipped, since the Moon’s longitude only increases and passes every boundary in order. That is the difference between the Moon’s list and the ingress lists on the planet pages of this family, where a planet turning retrograde recrosses a boundary and the list counts the re-entry as its own line.

Nothing in the count carries a meaning. It is the arithmetic of two periods, the sidereal month and the calendar year, that do not divide into one another, and a year that holds one entry more than its neighbor is a year whose last days happened to hold one more boundary crossing.

The English almanacs of the sixteenth, seventeenth and eighteenth centuries printed a table like this one every year. Bernard Capp’s history of the almanac describes the standard layout: a calendar with a column giving the Moon’s sign against each day, and facing it or near it a woodcut of a standing figure with the twelve signs placed on it from head to feet. Printers called the woodcut the Anatomy. Capp records that buyers expected it and that compilers who thought little of it kept it in all the same, so the figure and the Moon column stayed a pair.

Beside the two the almanacs printed a rule, and the rule was the reason the pair existed. It said that a surgeon was not to let blood, or otherwise cut, from the part of the body whose sign the Moon occupied on that day. The same rule stood in the Centiloquium, a collection of a hundred short sayings that the Middle Ages ascribed to Ptolemy, and in the printed phlebotomy manuals of the fifteenth and sixteenth centuries, among them the Fasciculus Medicinae printed at Venice, which set a Zodiac Man beside a figure marked with the veins a surgeon opened. The reason the texts gave was that the Moon drew the humors toward the part its sign governed, so that a vein opened there bled more than the surgeon intended.

Some almanacs printed the rule in verse under the figure, some as a line of prose, and some left it out, since their readers knew what the pair was for. Capp notes that the practice persisted in the popular almanacs long after the learned physicians had let it go, and that the woodcut persisted longer still.

All of that is told here as what the almanacs printed. This page prints the Moon’s sign and the region beside it because that is what the historical table held, and it prints no rule. It marks no day for anything and names no day as suited or unsuited to anything. Bloodletting itself ended as an ordinary procedure in the nineteenth century, as histories of medicine date it, and the almanac rule went out with the lancet it served.

The region column follows the list that runs through the whole tradition from Manilius to the almanacs. Manilius set it out in Latin verse in the first century: the head to the Ram, the neck to the Bull, the arms and shoulders to the Twins, and so on down to the feet and the Fishes, twelve signs to twelve regions in zodiacal order on a figure standing upright. The Greek writers had the same sequence, the Arabic introductions to astrology carried it through the Middle Ages, and Lilly in 1647 and Culpeper in 1651 and 1655 printed it in English with organs added to the regions the Latin had named.

The column here uses the wording most of the sources share. It reads head and face for Aries and feet for Pisces, as every source has it, and for the middle of the figure it names the organs the English writers added, so that Leo reads heart and back where Manilius alone wrote the flanks. Where the sources differ the column follows the later lists, and the Zodiac Man guide sets the four wordings side by side, row by row, and tells the history of each difference.

Two things about the list are worth saying plainly. First, it is a list of correspondences made by poets and astrologers, and none of those who held it tested it as anatomy or as medicine. Second, the list attached regions to signs and never to days or to people. The almanac rule added the day by way of the Moon, and this page takes the day away again. What remains in the column is the correspondence alone, printed as the texts printed it, in the past tense of a historical note.

The calendar is an astronomical table with a historical column. It is not a schedule of anything. The old almanacs used the pair of the Moon’s sign and the figure to mark the days on which a surgeon was not to open a particular vein, and some modern almanacs and handbooks print lists of days said to suit one activity or another by the Moon’s sign. This page carries no such list and no such marking, and nothing on it names a day as better or worse than another for any purpose.

It is not a reading of anyone. The region column says what the old lists gave each sign, and the table says which sign the Moon is in. Put together they say that on a given day the Moon stood in a sign to which the almanacs attached a region. They do not say that the day, the sign or the region has anything to do with any reader, and the page offers no form for a birth date, because a reader’s own chart plays no part in what the table shows.

It is not a void-of-course calendar, although the two share the Moon’s sign entries, computed the same way. The void-of-course Moon calendar on this site deals with the Moon’s last aspect in each sign, which this page ignores; this page deals with the sign and the history of what was printed beside it.

Finally, it is not a calculator in the sense the other tools of this family are. The temperament calculator applies a rule to a chart and names a result; the body map places a chart on the figure. The calendar applies no rule and takes no chart, so it has no result panel. It shows a committed table, month by month, under the notice that heads every page of this family: a description of what historical texts said, not a statement about anyone’s health.