Astrological Predictive Techniques | 2. Monthly Profections

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This is why such extremes of experience are found in the passage of time, and good is linked to bad, sorrow attends success, and in its inconstancy fortune maintains no steady course: to such an extent is it varied and changing, nowhere remaining the same; and by its commutation of everything in the lives of us all it has forfeited our trust.  (Manilius, Astronomica, 3.524-530, Goold trans., 1977, p. 206-207)

Profections for Smaller Time Periods

In the first article of this series, we looked at one of the simplest, most ubiquitous, and effective of ancient predictive techniques, profections.  Now, we’ll look at how astrologers applied this concept of profections to smaller time periods such as months, days, and hours. Therefore, if you are unfamiliar with profections, please read the first article to get acquainted before reading on.

Annual Profections Recap

When a native is born, the lord of the year is the lord of the house [ascendant] in which the native was born.  Thus count from the ascendant a year for each sign until you reach the year which you desire; the lord of that house is the lord of the year.  Look at the lord of this sign, whether it is a benefic or a malefic, and in the base-nativity how its position was and in which foundation it was.  From the base-nativity is known what is concerning him [the native] at the beginning of the year, and the beginning of the year is always when the Sun enters the beginning of the minute in which it was on the day of the native’s nativity. (Dorotheus, Carmen Astrologicum, Book IV-1.1-5, Pingree trans., p. 90)

Dorotheus goes on to discuss not only that the ruling planet (i.e. lord of the year) is important, but also the planets in the sign the Ascendant profects to, and the regards (i.e. aspects) of the planets to that sign (especially by opposition).

Variations on annual profections will be dealt with in greater depth in many future posts on predictive techniques, but Dorotheus has captured the main idea of the basic method pretty well.

Monthly Profections Basics

The monthly profection always involves moving (i.e. profecting) the Ascendant one sign per month. We start from the sign of the annual profection, which takes the first month. For instance, if one were 23 years old, born with Aries rising, then the annual profection would be to Pisces (24 would be first place, so 23 would be one back in the 12th place, Pisces). The first month after the solar return would be a Pisces month, with Jupiter as lord of the month. The next month would be an Aries month, with Mars as lord of the month, and so forth.

The simplest approach is to use the day of the month of your birthday as a marker.  For instance, if born on the 2nd of August, then you could have the 2nd of August to 2nd of September as the first month, 2nd of September to 2nd of October as second month, and so forth. This is the method I tend to use for finding a lord of the month. Early on in my studies of profections, it was the method that was recommended to me by Robert Zoller in his Diploma Course in Medieval Astrology (2003, Lesson 18, p. 17-18).

However, there was a greater diversity of opinion among ancient astrologers with regards to monthly profections. What did various astrologers of the Hellenistic and Persian periods have to say about monthly profections?

Opinions of Astrologers on Monthly Profections

Manilius on Smaller Profections

To every sign there comes an hour just once a day, a day twice in the month, a month once in the year, and a year once in twelve annual courses of the Sun.  (Manilius, Astronomica, 3.548-551, Goold trans., 1977, p. 207)

This passage is found in Manilius’s (1st century CE) discussion of an alternative method for profecting through the signs.  In another post dealing with additional profectional variants, I will address the other system preferred by Manilius. For our current purposes, we are focused on the more typical profection of the Ascendant.  Aside from the references to smaller units of profections, Manilius does make clear that the Ascendant profects to each sign once per year when it comes to monthly profections.

In terms of the smaller units, he notes that each sign gets a day twice in the month. I assume he was referring to the 2.5 day periods from dividing a month by 12. If each day were a new profection then half the signs would come up twice in the month and the other half would come up three times. Each sign comes up only once a day for hourly profections so these are 2 hour periods (either of an equal type or unequal based on planetary hours).

Al Biruni’s 13 Months

There is at least one notable exception in the literature to the 12-months per year rule. It occurs about 1,000 years after Manilius, with the noted Persian polymath Al Biruni (11th century CE):

When the signs and degrees of the yearly terms have been learnt, each year is divided into (thirteen) months of 28 days 1 hour 51 minutes and a sign to each given, so that the last month ends at the same degree as the radical ascendant has the same sign as the first, while the first month of the next year has the same sign as the year; similarly a sign is given to each of thirteen periods of 2 days 3 hours 50 minutes, the end of the last of these periods coinciding with the end of the monthly term. (Al Biruni, The Book of Instruction in the Elements of the Art of Astrology, 522, Wright, 1934, p. 95).

This 13-fold division of Al Biruni is atypical for profections. I don’t personally recommend it.

Ptolemy’s 2 1/3 Day Profections

The 13-fold division may have been an attempt to rationalize and refine some remarks by Ptolemy (2nd Century CE) referring to 28 day monthly profectional periods and 2 1/3 day daily profectional periods:

We shall discover the general chronocrators, then, in the manner described, and the annual chronocrators by setting out from each of the prorogatory places, in the order of the signs, the number of years from birth, one year to each sign,and taking the ruler of the last sign. We shall do the same thing for the months, setting out, again, the number of months from the month of birth, starting from the places that govern the year, twenty-eight days to a sign; and similarly for the days, we shall set out the number of the days from the day of birth, starting with the places which govern the months, two and a third days to a sign. (Ptolemy, Tetrabiblos, Book 4, Ch. 10, Robbins trans., 1940, p. 453).

Ptolemy used an approximation of the orbital period of the Moon. The orbital period is almost 28 days. The time it takes for the Moon to travel 360* in the zodiac.  Ptolemy took this as a month, rather than either the approximate synodic period of the Moon (almost 30 days, time between New Moons) or 1/12 of a year (just over 30 days), which seem to be more commonly chosen.

Other Hellenistic Astrologers

We will look at other Hellenistic astrologers to explore how they divided the time.  We will ignore Dorotheus (1st century CE) in this matter, as he presented totally different methods for finding month and day lords, that don’t seem to be based on profections.


Valens (2nd century CE) added much to the use of profections. He advocated profecting all the different planets and points to each other(with particularly stress on the Ascendant and Lights). This system of transmitting and receiving will be treated in another article. It is a variant on the basic idea of profections.

However, despite the large and complicated exposition of annual profections that Valens provided (c.f. Book 4, Ch. 11-13), he did not treat of monthly profections. Note that it is possible that I’ve overlooked some mention of monthly profections in his massive text. He seemed to have used different methods, including those used by Dorotheus, to find month and day lords.


Julius Firmicus Maternus (4th century CE) also advocated annual profections, but used a different technique for periods less than a year (c.f. Mathesis, Book II, Ch. 27 vs. Ch. 28).


Paulus Alexandrinus (4th century CE) did discuss monthly profections (c.f. Introductory Matters, II.31). However, he was not specific about how long the month should be. By contrast, he did specify that each daily profection should last one day, rather than 1/12 of a month.  This would yield about 2.5 cycles of 1 day profectional periods in a month, rather than the oft-found one cycle of 2.5 day periods.

I am not myself an advocate of using daily profectional lords at all. However, I can see the logic in using either the 2.5 day or the 1 day periods. If one is so inclined to use daily profections at all, then one should tinker to find which variety is most effective.

Perso-Arabic Astrology

In Persian predictive methods, the stress is on the annual profection of the Ascendant and its indicated Lord of the Year. There is little concern with monthly profections.


Masha’allah discussed the Lord of the Year from the annual profection before other methods in his discussion of annual methods in Book IV of the Book of Aristotle. He even delineated each planet as Lord of the Year (c.f. Book IV.1-7). He did not employ profections for figuring month and day rulers.

‘Umar al-Tabari

‘Umar al-Tabari similarly placed a great deal of stress on annual profections. He employed a continuous 30* per year approach rather than discrete annual jumps by sign (to be addressed in a future article). However, he gave no discussion of monthly profections in Book II of his Three Books on Nativities.

Abu Ma’shar

Abu Ma’shar also emphasized the annual profection of the Ascendant. Like al-Tabari, he employed a continuous degree approach. The profected sign of the Ascendant is critical to his predictive method outlined in his On the Revolutions of the Years of Nativities. It received a lot of attention and delineation material, particularly in Book II.  However, monthly profections get only a very small mention. They are mentioned in Book IV in which he discussed rulers of shorter periods, He specifically uses a 30 day monthly profectional period, a 2.5 day daily profectional period, and even a five-hour hourly profectional period. Thus it is clear that he sees division by 12 as the key to deriving smaller profectional periods.

However, it should be noted that these profections of periods under a year are one of the last things discussed in his discussion of rulers of periods less than a year, and he doesn’t refer to any corresponding Lord of the Month, Day, or Hour. Instead, Ma’shar apparently used them aspectually. It’s unclear whether he actually used profections of smaller periods in natal prediction, or was simply conveying the idea behind them as a possibility for fine-tuned investigation.

In a given annual profection, profect the four chief indicators through the months at a rate of 30° per month. […]  For all of these, direct them through the next 30° (representing one month) at a rate of one day per degree, noting the planetary bodies and rays encountered. (Abu Ma’shar, On the Revolutions of the Years of Nativities, Book IX, Ch. 8, Dykes trans., 2010, p. 205-206).

Conclusion: A Confusing Legacy

In conclusion, monthly profections existed in the Hellenistic period but most Hellenistic astrologers didn’t use them for time lords. Their absence in most texts can be contrasted with the prevalence of annual profections.

When monthly and daily profections are employed, it is difficult to tell which time period to use. They can be based on a prototypical conception of the time period (such as 28 or 30 days for a monthly, and 1 day for a daily). On the other hand, they can be treated as 1/12 of the greater period (such as just over 30 days for monthly and 2.5 days for daily). There are conflicting indications given in the early texts when they are discussed. Interested readers should experiment to find the style that is most effective.

Personally, I do feel that adding monthly profections to one’s predictive toolbox is worthwhile. I think that their frequent neglect in ancient predictive material is in part owing to a general emphasis on larger time frames and bigger events. Transits are also often neglected in ancient astrology for the same reason. Transits too should not be neglected in the practice of the art in this fast-paced modern era of easy computation.

Biruni, A. (2006). Book of Instructions in the Elements of the Art of Astrology. (R. R. Wright, Trans.). Bel Air, MD: Astrology Classics.
Ma’shar, A. (2010). Persian Nativities III: Abu Ma’shar on Solar Revolutions. (B. N. Dykes, Trans.). Minneapolis, MN: The Cazimi Press.
Manilius, M. (1977). Astronomica. (G. P. Goold, Trans.). Cambridge, MA: Loeb Classical Library.
Ptolemy, C. (1940). Ptolemy: Tetrabiblos. (F. E. Robbins, Trans.). Cambridge, MA: Loeb Classical Library. Retrieved from
Sidon, D. of. (2005). Carmen Astrologicum. (D. Pingree, Trans.). Abingdon, MD: Astrology Center of America.
Image Attribution

Feature image of “clock boy” (cropped) by malias (Flickr) [CC BY 2.0 (], via Wikimedia Commons



Blogger interested in all things astrological, especially Hellenistic, medieval, Uranian, and asteroid astrology.

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