Introduction to the Planetary Hours and Days

The planetary hours are based on an ancient astrological system, the Chaldean order of the planets. This is the sequence: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, then repeating endlessly Saturn, Jupiter, etc. The Chaldean order indicates the relative orbital velocity of the planets.

From a heliocentric perspective this sequence also indicates the relative distance of the planets from the center of their orbits, i.e., the distance of the planets from the Sun (with the Sun switching places with the Earth in the sequence) and the distance of the Moon from the Earth.

From a traditional geocentric perspective the Chaldean order also shows the arrangement of the planetary spheres.


8 spheres

The Sequence of the Planetary Hours

The planetary hours use the Chaldean order to divide time. Each planetary hour of the planetary day is ruled by a different planet. The planet that rules the first hour of the day is also the ruler of the whole day and gives the day its name. Thus the first hour of Sunday is ruled by the Sun, the first hour of Monday is ruled by the Moon and so on.


planetary hours day

planetary hours night

However, the planetary hours are not the same as the sixty minute hours beginning at midnight that we use for normal timekeeping. The planetary days are divided into twenty four planetary hours with the first hour of the day beginning at sunrise and the last hour of the day ending at sunrise of the next planetary day. The period that extends from sunrise to sunset (daylight) is divided into twelve hours and the period extending from sunset to sunrise of the next day (nighttime) is also divided into twelve hours giving the twenty four hours of the planetary day.

Accordingly, as the duration of daylight and darkness varies except at the Vernal and Autumnal Equinoxes, on a particular planetary day the length of the hours of the day will differ from the length of the hours of the night. Thus another name for the planetary hours, says William Lilly, the renowned English astrologer, is the unequal hours. Christian Astrology, [London, 1647] page 482.


The Planetary Hours and the Names and Sequence of the Days of the Week

As Lilly notes there are seven days of the week and seven planets and each planet rules or is lord of, one day: Sunday, the Sun; Monday, the Moon; Tuesday, Mars; Wednesday, Mercury; Thursday, Jupiter; Friday, Venus; and Saturday, Saturn. William Lilly, Christian Astrology, p. 482. The origin of the names of the days are explicitly planetary in medieval Latin: dies dominici (Sunday, the lord's day), die Lune, die Martis, die Mercuri, die Jovis, die Veneris, die Saturni.

In English the Teutonic equivalents of the Greek and Latin gods have been used for some of the names of the days, i.e. Tuesday is Tiw's day, the Teutonic god of war; Wednesday is Wotan's day; Thursday is Thor's day; Friday is Frigg's day. The 7 day week comes directly from astrology, the 7 days deriving from their lords, the 7 planets. We would note that from the introduction of the week in the classical period that the order has never varied or been interrupted. For example the adoption of the Gregorian calendar changed the date, but not the endless cycle of the days of the week.

As we can see the sequence and names of the days of the week are not in the Chaldean order, but nevertheless the sequence and names of the days of the week are closely connected to the Chaldean order. Two processes interact to produce the sequence of the days of the week: (1) the fact that the planetary hours follow the Chaldean order and; (2) the fact that the planet that rules the first hour of each day rules the whole day and gives the day its name.

Figure One is the standard diagram of the planets arranged in a circle in the Chaldean order. Starting with the Sun and then following the order of the days of the week and their planetary rulers, i.e. Moon, Mars, Mercury, Jupiter, Venus, Saturn, produces a seven pointed star, the heptagram of the week.


7 pointed star of week Figure One - Heptagram of the Week

Figure Two is an elaboration of the heptagram of the week adding the planetary hours. Note that there are seven large, bold planetary glyphs arranged in a large seven pointed star. These represent the planetary days, e.g., Sun rules Sunday, etc. The numerous small, unbolded glyphs represent the planetary hours and show their rulers.

Start with the Sun, the ruler of Sunday. Look for the large bold glyph of the Sun in the lower right hand corner of the diagram. Seven smaller glyphs are arranged around it in a circle. Look in the seven glyphs for the glyph of the Sun. The underlined glyphs indicate the first planetary hour of the day, in this case Sun hour, the first hour of Sunday. The next hour is represented by the glyph of Venus to the left of the underlined glyph of the Sun, thus the second hour of Sunday is ruled by Venus.


planetary hour heptagram Figure Two - Planetary Hour Heptagram

So we follow the Chaldean order, from Venus (2nd hour of Sunday) to Mercury (3rd hour of Sunday) to the Moon (4th hour of Sunday), to Saturn (5th hour of Sunday), etc., etc, until we get to the medium size glyph of Saturn in the inner circle (12th hour of Sunday). Saturn is the ruler of the last hour of daylight on Sunday which ends with sunset.

Staying in the inner circle keep going up from Saturn to Jupiter (the 1st hour of Sunday night, beginning with sunset) up to Mars (2nd hour of Sunday night) and then leave the inner circle heading in a straight line to the large Moon glyph, keeping in the Chaldean order by going to the Sun (3rd hour of the night).

We then continue into the circle around the Moon glyph until we reach Mercury which is the ruler of the 12th hour of Sunday night and thus the ruler of the 24th hour of the whole planetary day of Sunday. Therefore we see that the next planetary ruler in the Chaldean order is the Moon, the ruler of the first hour of Monday. By following the diagram in the Chaldean order we can see the interaction of the planetary hours and the names and sequence of the days throughout the week.

Figure Two shows how the sequence of the planetary hours in the Chaldean order and the rulership of the planetary day by the first planetary hour ruler produces the order and names of the days of the week. Thus we can see that the order and names of the days of the week are not merely conventional, but part of an ancient natural and highly ordered astrological system.

This is just scratching the surface of an incredibly inherent order. For even more information on the Chaldean Order, the planetary days, hours, plus the planetary minutes and seconds, check out the Third Planetary Order page, which details my discovery of three basic ordering sequences based on the number 7, which are the Chaldean Order, the days of the week sequence, and the amazing Third Planetary Order!


Calculating the Planetary Hours

Our first practical problem is how to calculate the planetary hours. There are many online planetary hours calculators and apps which you can Google search. Renaissance Astrology offers TPHP ("The Planetary Hours Program") an easy to use computer program for Windows that provides detailed and accurate planetary hour information for automatically for thousands of predefined locations in the U.S. Latitude and longitude can also be entered by hand for non-U.S. locations.

To calculate the planetary hours by hand get your local sunrise and sunset times from the newspaper or the US Naval Observatory. Take the time from sunrise to sunset convert to seconds and divide by twelve to get the length of each planetary hour in hours, minutes and seconds or minutes and seconds for the day. Take the time from sunset to sunrise the next day in seconds and divide that by twelve, then convert to hours, minutes and seconds or minutes and seconds for the length of each planetary hour by night. The calculations need to be done in seconds, because otherwise rounding error start to accumulate. Then starting with the planet that rules the day, e.g. Saturn for Saturday, follow the Chaldean order and assign the proper planet to each planetary hour of the day and night that you have just calculated.


Using the Planetary Hours for Elections and for Magic

The planetary hours are a secondary technique in traditional horary and electional astrology. For example, we use the planetary hour as part of determining technical radicality in horary charts. Here is an extensive discussion of the many uses of the planetary hours in Renaissance astrology.

One of the things that I have my students studying planetary magic do is to chart the planetary hours and then watch how events line up with the planetary hours for a week. We can see, for example, arguments happening in the hour of Mars, profit in the hours of Jupiter, pleasure in the hours of Venus, and so on. My estimate is that the planetary hours correspond about 60-70% to events, though your results may differ.


zodiac clock

By choosing to do an activity within the appropriate planetary hour you can enhance the success of the activity. For example, to ask someone out on a date, you could use Venus hour. For an important phone call, e-mail or text, Mercury hour. For a profitable business deal, Jupiter and so on. Here is more information about traditional planetary rulerships and the things and activities ruled by each planet.

Here are elections with planetary hours by the English astrologer Henry Coley from his 1676 Clavia Astrologiae Elimata. Keep in mind that planetary hours may or may not be effective as the sole factor for an election. In traditional astrology we always try to predict future events and to elect times based on multiple astrological factors, not just one. Planetary hours can be significant, but for best results we need to add them with other factors as part of a full chart prediction or election.

One of the most important uses of the planetary hours is for magic. Here is an article on the use of the planetary hours in astrological magic by the famous Renaisance philosopher Marsilio Ficino. Here is an excerpt on planetary hours elections in the Key of Solomon, a famous medieval grimoire.

Planetary hours are a key election factor in the creation of authentic Renaissance astrological talismans. Here are our Currently Available Talismans. Many of the planetary talisman recipes from the famous astrological grimoire, the Picatrix and from Cornelius Agrippa require that the talisman be made in the planetary hour of the appropriate planet.

My standard planetary talisman recipe is to make the talisman with the selected planet (1) dignified, (2) rising or culminating (3) in the planetary hour of the planet, (4) with the planet and the Moon unafflicted. While some recipes call for the planetary day, Picatrix, Agrippa and my personal experience is that the hour is more important than the day. Planetary hours are certainly more precise and focused than the planetary day.


Jupiter talisman design Jupiter Talisman Design

Learning the Magic of the Planetary Hours

Learn how to use the power of the planetary hours through Renaissance Astrology courses. The Planetary Magic Mini-Course is a self contained web course course that requires no knowledge of magic or astrology and provides a complete introduction to the magic of the planets and the planetary days and hours. Included is TPHP, the Planetary Hours Program, an easy to use program for Windows that instantly calculates the planetary hours.

Also included are traditional talisman images from by the esoteric artist Nigel Jackson which students can download and use to make their own talismans. Complete instructions for talisman ritual and consecration for each planet are provided.

The Astrological Magic Course is available on both CD and by download and teaches the full range of medieval and Renaissance astrological magic including the the magic of Cornelius Agrippa, Marsilio Ficino and Picatrix including planetary hours.

Students who successfully complete the Astrological Magic Course will be able to elect times for and construct a wide variety of astrological talismans, including planetary, lunar mansion, fixed star, decan, house, natal and other talismans. No previous astrological or magical knowledge is required and all necessary astrological technique will be taught in the course.

The Astrological Magic Course on both CD and via download includes the Planetary Magic Mini-Course, Decan/Face Mini-Course and Mansions of the Moon Mini-Course, Mansion Tracker, lunar mansions software, TPHP, planetary hours software, Decanichron, decan/face software and PMP, the planetary magic program. The Astrological Magic Course on CD includes free paperback copies of Secrets of Planetary Magic, Secrets of Planetary Ritual, De Imaginibus and the Mansions of the Moon book. Astrological Magic Course download students will need to purchase these books separately either as paperback or Kindle e-books.


Deeper into the Planetary Orders & Planetary Minutes & Seconds

You can follow me even deeper into my explorations into the incredible underlying order revealed by planetary days and hours as I delve into modular arithmetic and discover the amazing Third Planetary Order which along with the Chaldean Order and days of the week sequence govern all 7 fold operations.