Planetary Rulers of the Hours, from Scratch

As part of the Grimoiric Magical Tradition of the Middle Ages, wisdom from more ancient cultures contributed to the development of a complex magical theory. Alchemy, astrology, and mediumship all helped to shape the traditions that made up a complex ceremonial  magical system, parts of which have survived to today. Within the realm of medieval astrology is a system of determining the most auspicious times for magical workings, which is still used by witches today.

In the expanse of the sky above us, float the stars and planets. Their movement has influenced the magical schools that have developed around the globe since humans had the capacity to look up. Planets got their name from the fact that they were a special kind of star that wandered through the fixed stars (planētai means “wanderers”). There were 5 planets visible with the naked eye to the first civilizations.

Highly accomplished astronomers, the Babylonians had a complex theology surrounding these planets, believing that the planets were deities, each one governing the universe from a transparent sphere, called a “heaven,” that revolved around the Earth. Each sphere was larger than the last and enveloped the smaller spheres, much like layers of an onion, with the Earth at the center. 

Ptolemy organized the 5 planets, along with the Sun and the Moon, based on their speed, so 7 heavens encased the Earth with the Moon being the fastest and closest to Earth, then Mercury, Venus, the Sun, Mars, Jupiter and finally Saturn, which was the slowest.

The sphere outside of Saturn was the heaven that held the field of immovable stars, including the Zodiac. Outside of that were the divine spheres. Before birth and after death, every soul had to come or go from Earth by passing through the heavens. As we passed through these levels, our spirits would pick up personal qualities - affected by being exposed to the powerful vibration of these spheres.

This was the origin of what we now know as Astrology, because it was postulated that the spheres would influence behavior. These heavenly spheres were viewed as endowing their power, not just on the spirits of people, but also on the moments of the day and on the days of the week. The priests of each deity would calculate the most auspicious times in every day to work with their patrons.

It’s a common practice today to reference a table of the rulers of the planetary hours before casting a spell. This gives us the chance to do our spell work during a time of day that vibrates with the most appropriate magical “frequency” for the intended purpose. There are many good online calculators that can provide you with a very quick and accurate table of hourly rulers. But what if you can’t use an online tool? What if you’re doing your spells in a cabin in the woods with no internet access? Every witch should have the ability to chart the rulers of the hours. Once you understand how these rulers came to be, you can create that chart easily from memory.

We have seven days of the week and each day belongs to one of the planetary rulers to be the primary ruler of the whole day. Sunday ("Sun-day") is the most obvious example and the primary ruler is the Sun. Monday and Saturday are ruled over by the Moon (“Moon-day”) and Saturn ("Saturn's-day"), respectively. The remaining days of the week are based on their association with Norse deities. Tuesday is ruled by Týr ("Týr's-day"), Norse god of law and heroism, who corresponds to the Roman god, Mars. Wednesday is ruled by Woden ("Woden's-day") who corresponds to the Roman god Mercury; both are gods of travelers, magic and learning. Thursday is ruled by the Norse god of thunder ("Thor's-day") and corresponds to the Roman god, Jupiter.  Venus, goddess of love, who is seen in the Norse pantheon as Freya ("Freya's-day") rules Friday.

A ruler of a day governs the first hour, which begins at dawn. The rulers of each of the subsequent hours are laid out in a specific order that forever repeats throughout the 24 hours of each of the seven days of the week. Let’s start with an example day – Monday – which is ruled by the Moon. This means that the Moon will always be the ruler of the first hour on Mondays. Each daily period following the Moon’s governance will be ruled by one of the remaining six planets, but always in the same sequence. To find this sequence, write out a repeating sequence of the planets in order from slowest to fastest. We know the Moon is ruler of the first hour on Mondays and it is the fastest planet, so it is the last planet in the speed sequence; we must return to the slowest planet and begin the sequence again. The second hour will be Saturn, the third will be Jupiter, then Mars, the Sun, Venus, Mercury and lastly, the Moon again. Continue to repeat that sequence until there are 24 rulers on your list. You have listed the sequence of the rulers of all the hours from sunrise on any Monday, through the night time, to sunrise on the following Tuesday morning.

If you continued the sequence into Tuesday and the remaining hours of the week, you would create a chart like the one below. Notice how the sequence for all the hours of the week flows from day into night, then into the next day, then continues without change through all the hours of each day and night for the rest of the week. The sequence determines which day of the week has arrived because of the particular ruler of the first hour. Hour 1 of the daytime always begins with sunrise. Hour 1 of the night time (or hour 13 in some tables) always begins with sunset.

In the contemporary age, the period of the day that we call an “hour” is a specific length – always 60 minutes, each made up of 60 seconds. But the hours ruled over by each of the planetary rulers are not always 60 minutes long. This is because the Babylonians reckoned their hour, not as a set length as we do, but as one-twelfth of the total amount of daylight time or darkness. That is, both the day time and the night time, separately, were divided into twelve equal periods based on sunrise and sunset. Starting on the Equinoxes, the amount of daylight we experience between sunrise and sunset is more than 12 hours in spring and summer and less than 12 hours in autumn and winter. So if we are in spring or summer, when the day time totals more than 12 hours, each one-twelfth period of that time is going to last greater than 60 minutes. In autumn or winter, each one-twelfth period will be less than 60 minutes. Clearly, continuing to call these periods "hours" is confusing, so I will only call them periods from this point onward.

To determine the length of each period, you will first need to know the times of sunrise and sunset. The times of sunrise and sunset are actually calculated by astronomers based on your location on the globe and the date of interest. They will be different for each latitude because of the curvature of the Earth, the tilt of its axis and the date. These times are commonly published in local newspapers and almanacs, as well as pagan calendars, but are also readily available online through reliable sites like NOAA. For the sake of this exercise, let’s assume that we looked in our almanac to find that our sunrise time will be 6:42 AM, our sunset time will be 7:32 PM and we decided that the best period for our spell will be the hour of Mars.

Step 1: Convert the sunset time into the 24-hour clock.
Simply add 12 to any time between 1:00 PM and 11:59 PM. For example, a sunset of 7:32 PM will become 19:32.

Step 2: Convert clock times into decimal hours.
This allows us to use standard math until the very end. The arithmetic of decimals works easily on a calculator, while arithmetic of clock time does not. Doing these calculations on paper is even worse! You can convert clock times into decimal hours by dividing just the minutes by 60. So our sunrise time of 6:42 AM will become 6.78 (42 ÷ 60 = 0.78). Our sunset time of 19:32 will become 19.53 (32 ÷ 60 = 0.53).

Step 3: Subtract the smaller clock time from the larger.
19.53 – 6.78 = 12.75 hours
This result is the amount total of daylight time that will shine on our Monday; there are 12.75 hours of daylight between sunrise and sunset.

Step 4: Divide this total time by 12.
12.75 hours ÷ 12 periods = 1.06 hours/period
This means that every period ruled by each planet, beginning with the Moon, will be 1.06 hours long.

Step 5: Find the start and end of the period of interest.
Remember that our period of interest is ruled by Mars. If we refer to our list of the rulers of Monday, we find that Mars rules the 4^th period. Multiply the length of the periods, which we found to be 1.06 hours/period, by the number of the period for Mars on our day, which is 4. This gives us a result of 4.24 (1.06 hours/period x 4 periods = 4.24 hours). The Mars period will end when the next period begins, so we can multiply by 5 to find the end time: 5.30 (1.06 hours/period x 5 periods = 5.30 hours).

Step 6: Add the period start and end times to the decimal time of sunrise.

Period of Mars, starts: 6.78 (sunrise) + 4.24 hours = 11.02

Period of Mars, ends: 6.78 (sunrise) + 5.30 hours = 12.08

Step 7: Convert both of the times back to clock time.
Simply multiply only the minutes by 60.

Period of Mars, starts: 11.02 becomes 11:01 AM (.02 x 60 = 1.2 minutes, rounded to 1).

Period of Mars, ends: 12.08 becomes 12:05 PM (.08 x 60 = 4.8 minutes, rounded to 5).

Step 8: Convert any result that is 24-hour time back to 12-hour time.
Subtract 12 from any clock times from 13 to 24.

As witches, we do most of our spells after sunset, when the darkness provides us with protection and secrecy and helps to generate the appropriate head-space. Finding the correct period after dark often produces more difficulty because of the transition from PM to AM at midnight. However, a simple reversal can resolve all difficulty, though the process seems unconventional. I find that the best way to handle the difficulty is to treat the night as if it was the day, then work all the steps normally.

Your periods will start with sunset and will end with the sunrise on the following date. Convert the AM times to 24-hour time, instead of the PM times. Complete all calculations the same. At the very end, convert any time between 13:00 and 23:59 back to 12-hour time as AM, instead of as PM.

I recommend keeping all values rounded to two decimal places until step 7. This minimizes any distortion of the period start times. I also find it helpful to ensure that my spell work happens at least 5 minutes past the chosen period start time, just to be sure I’m well past any minutes affected by rounding, putting me solidly into the correct period before I begin.

Whenever possible, I advocate using a reliable planetary rulers calculator, but if you can’t get to one, you should have this technique tucked in your book of shadows as a back-up plan.