Were You Born in the Moon's Dark Days?

What are the Moon's dark days?

The dark days are the last three days of the Moon's cycle, before the exact New Moon. The Moon rises just ahead of the Sun as a thin crescent at dawn, then disappears into its glare. Three days out of a cycle of 29.5 days means that about one birth in ten falls in them.

The Moon reappears a day or two after the New Moon as a thin crescent in the west after sunset, and a new month begins. In the Athenian calendar the first day of the month was the noumenia, the new moon, and the last day had its own name, henē kai nea, “the old and the new”: a day that belonged to both months at once.

What was Hekate's supper?

On the last day of the month, Athenian households set out a meal for Hekate, goddess of the crossroads, at a crossroads or at her small shrine by the door. It was called Hekate's supper, the Deipnon. Whoever set it down did not look back at it, and in the dark the poor came and ate it.

The comic poet Aristophanes joked about it in Wealth: in his line, the poor make Hekate's supper disappear before it is even served. The same night the house was cleaned out. Leftovers from offerings and the incense burner carried through the rooms were taken out to the crossroads too.

“the poor make it disappear before it is even served”Aristophanes · Wealth (Plutus) · tr. E. O'Neill

Hekate is usually shown carrying two torches. On the nights the Moon gives no light, hers are the only ones on the road.

What does “under the beams” mean?

In Hellenistic astrology a planet within about 15° of the Sun is “under the beams”: hidden in the Sun's light and unable to show itself. The Moon is under the beams for roughly the last day before the New Moon and the first day after it. Such a planet was read as hidden, working out of sight.

So a dark-days birth puts the Moon, the planet of the body and of daily life, at the very end of its cycle and about to renew. How that plays out depends on the rest of the chart, starting with whether you were born by day or by night.

What were the other Moon phases?

Every other birth falls somewhere in the Moon's monthly round from New to Full and back. The calculator names your phase, how much of the Moon was lit, and how many days it was from the New Moon. The table shows what the sky looked like in each phase, counted in days from the New Moon.

What did the old astrologers say about being born at each phase?

The Hellenistic astrologers did not stop at four quarters. Paulus Alexandrinus, writing his textbook around 378, counts ten figures the Moon makes with the Sun and notes that some add an eleventh. She is at conjunction on the Sun's degree, coming forth one degree past it, and rising at 15 degrees, when the first thin line of light shows. Then come the crescent at 60°, the half Moon at 90°, the doubly convex Moon at 120°, his "full Moon" at 150° and the whole Moon at 180°, and the same figures again as she wanes (Introductory Matters ch. 16). In Schmidt's translation, "full Moon" names 150° and the true opposition is the "whole Moon".

Vettius Valens, in the 2nd century, notes that the physicists count seven phases and records the eleven he found listed by earlier writers, then says what each one shows in a birth chart. He also gives each stretch of the month to a planet, counted in days from the New Moon (Anthology II, "What Each Phase Indicates"):

On that scheme the dark days fall in the last crescent and last visibility, in the stretch Valens gives to Saturn. Read it as one testimony among many in the chart, never a verdict by itself.

Firmicus Maternus, writing in Latin in the 4th century, ties the phases to the body. "We feel in our bodies the increases of the waxing Moon and the losses of her waning," he writes, and he gives the Moon care of the body's whole substance (Mathesis IV.1). Again and again in his fourth book he judges the same meeting twice, once for a waxing Moon and once for a waning one. With Saturn, a waxing Moon loses an inheritance, and in time the native builds up means again by their own efforts. A waning Moon with Saturn gives parents of low birth or in poverty, a mother who is sickly or dies a violent death early, and a native who is weak and sickly (IV.2).

Dorotheus of Sidon uses the same quarters for choosing a time rather than reading a birth. From the Moon's first light to her first square a purchase is fair; from the first square to the opposition is the time to sell; from the opposition to the last square, the time to buy (Carmen V.44 in Dykes' numbering, V.43 in Pingree's).

William Lilly, writing in English in 1647, keeps the idea in his table of a planet's strengths: the Moon increasing in light counts among her strengths, decreasing in light among her weaknesses. He also gives the later numbers for the Sun's glare: a planet is combust within 8°30' of the Sun, under the Sunbeams until 17° away, and in the heart of the Sun, cazimi, within 17 minutes of arc, which strengthens it instead (Christian Astrology, ch. XIX).

So the phase tells you whether your Moon was gathering light or giving it away. I read that as growth or release, and the old texts weigh it together with her sign, her house and the planets she was meeting.

How does the Moon phase calculator work?

The calculator finds the New Moons on either side of your birth in a table of every New Moon from 1920 to 2031, computed to the minute with the open-source Astronomy Engine library. Your phase follows from where your birth falls between them. A birth time and time zone make the result exact.

Checked against a second, independent ephemeris, the PyEphem library, all 1,387 New Moons in the table agree to within a minute, and to 17 seconds on average.

Without a birth time the calculator uses midday. The Moon moves about 12° a day against the Sun, so that is close enough everywhere except at the edges of a phase. When your birth date sits near one, the result says so and asks for your time.

A Personal Ritual is timed the same way: by the day, the planetary hour and the phase of the Moon, read from your own chart.

Common questions

Is the dark Moon the same as the New Moon? Not quite. In astronomy the New Moon is the exact moment the Moon passes the Sun. The dark Moon is the stretch around it when the Moon can't be seen. The ancient month was set by what people could see, so dates for Hekate's supper and the modern almanac can differ by a day.

I was born just after the New Moon. Does that count? You were born at the crossing itself, still in the dark but on the far side: in Athens, the first day of a new month. The calculator marks it as the threshold rather than the dark days.

When are the next dark days? The calculator shows them from today's date. They come every 29.5 days and start three days before each New Moon.

Does the Moon's phase decide my personality? No single factor does. The phase is one fact about your Moon. Another is her lunar mansion, the station of her path she stood in. Its sign, house and condition, and how it works with your Sun and rising sign, say far more.