In the old grimoires there are many references to planetary days and hours. For instance a wand might need to be cut from a tree on the day and hour of Saturn and then consecrated on the day and hour of Mars. It was understood that, much like in divinatory astrology, an action partakes of the astrological characteristic of the moment it is done. By calculating the planetary day and hour of an event one can gain insight over the immediate and occult influences effecting that action.
There are at least two different ways planetary days and hours are calculated. The first is the most common method found in Western esotericism. References to this method, also known as the “uneven hours” can be found from the Key of Solomon to the writings of Agrippa. The second variation is derived from Talmudic and Kabbalistic sources. Both versions are similar but differ in detail and will be discussed separately.
Western Method
Planetary Days
There is no calculation necessary for finding the planetary days as they are set in a specific order:
As can be seen the planetary days follow the order of the days of the week.
Calculating Planetary Hours
Planetary hours are calculated as follows: Find the time of sun rise and sun set in your area. Calculate the total number of minutes between those times and divide it by twelve. These are the hours of a planetary day. Find the time of sunset and the next day’s sun rise in your area. Calculate the total number of minutes between those times and divide it by twelve. These are the hours of a planetary night. Because sun rise and sun set change each day, growing and shrinking in length, the daylight hours and evening hours are rarely the same length, thus they are known as the “uneven hours”. Also note that a planetary hour is not necessarily, and in fact not likely, to ever be 60 minutes long.
Placing the Planetary Hours
While the planetary days follow the order of the days of the week, the planetary hours within each day follow the Chaldean order of the planets. This order is also the order the planets are said to be created in according to Kabbalistic and Talmudic sources.
As can be seen this follows the order of the planets from furthest away from the Earth to the closet. When placed as planetary hours these seven planets repeat endlessly throughout the week.
Each planetary hour of a planetary day is dominated by a different planet according to the above order. The first hour of each planetary day. Thus the first planetary hour of Monday is ruled by the Moon, which also holds sway over the entire planetary day. The system of planetary hours is demonstrated in the follow charts:
Example
What follows is an example of finding the planetary day and hour. In this example our location will be Chicago, Il and the date will be January 1, 2007. We will be looking for the planetary hours for 13:38 or 1:38 PM and 18:50 or 6:50 PM.
January 1, 2007 was a Monday, indicating that the planetary day is that of Luna. Now we need to find the times of sunrise and sunset for January 1 in Chicago as well as sunrise on January 2, which will mark the end of the planetary night. Sunrise on January 1, 2007 for Chicago was at 07:18. Sunset occurred at 16:30 or 4:30 PM. Sunrise on January 2 was also at 07:18.
There are 9 hours and 12 minutes between sunrise and sunset on this day or 552 minutes. 552 divided by 12, for the 12 planetary hours during a planetary day, yields 46 minutes. Thus each planetary hour lasts 46 minutes. Because it is winter the length between sunset and sunrise is much longer. For this date there were 14 hours and 48 minutes between sunset and sunrise or 888 minutes. This is again divided by 12, giving us 74 minutes per planetary hour, demonstrating why the planetary hours were also called uneven hours.
We must now find the planetary hours for 1:38 PM and 6:50 PM. We will begin with 1:38 PM. Look to the chart of planetary hours for both day and night. The first planetary hour for Monday is ruled by the moon. On January 1, 2007 this began at 7:18 and lasted for 46 minutes, ending at 8:04 AM. Thus the second planetary hour began at 8:04 and lasted another 46 minutes until 8:50. To find the planetary hour that 6:50 PM falls in we follow the same method, beginning at 4:30 PM and adding periods of 74 minutes. For example the first planetary hour of the night for Monday is Venus, which on this date began at 4:30 and lasted until 5:44 PM. The charts below shows the results of all our calculations.
The above charts show that 1:38 PM fell during the planetary hour of Jupiter and that 6:50 PM fell during the planetary hour of Mercury.
The Jewish/Kabbalistic Method
Planetary Days
The Jewish/Kabbalistic method is similar to the Western method. There is, in fact, no difference in the way the hours are calculated. The difference lies in when a day is considered to begin. The Jewish system of date keeping, much like other Semitic calendrical systems, considered a day to begin at sunset the previous day when viewed on a Western solar calendar. So, unlike in the Western, solar version where each day is the equivalent of a single planetary day in the Jewish/Kabbalistic version each day contains a part of two planetary days. For instance the planetary day of Saturn, which is associated with the Jewish Sabbath, begins at sunset on Friday night and ends on sunset on Saturday night. Below is a list of the week days associated with their proper planetary days, wherein the first day contains the planetary hours of the night and the second day contains the planetary hours of the day:
Planetary Hours
Because Judaism begins each of its days at sunset of the day before, according to the modern Western calender, the nighttime hours are shifted forward one day in comparison to the Western version. See the chart below, which appropriately begins with the planetary hours of the night rather than the day:
Example
Because of this difference the data in the above example will yield slightly different results. The first time, January 1, 2007 at 1:38 PM, is on Monday before sunset. This means that it is on a different planetary day than the second time at 6:50 PM. The 1:38 PM time is during the daylight hours of the day of the moon and thus there is no difference between this version and the Western version. However the 6:50 PM time is after sunset and thus is on the next planetary day, the day of Mars, yet it still falls during the second planetary hour of the day, which is ruled over by the sun.
Using Planetary Days and Hours
The Western Hermetists and the Kabbalists, while both occasionally employing planetary days and hours in their work understood their usages somewhat differently. Agrippa (De Occulta Philosophia II:XXXIV) tells his reader that following the planetary days and hours is necessary to “work according to the celestial opportunity”. Examples of this are found in many of the medieval and Renaissance magical texts. For instance the fourth book of the Lesser Key of Solomon, “Salomon’s Almadel Art”, tells us that the Almadel, a special seal or magical symbol carved in wax, is to have the names of God engraved upon it in the day and hour of the sun. The implication is that doing so at this time would imbue the names with the astrological qualities of the sun. The planetary keywords can help you with the overall influence of each planet and are in the chart below.
While the Jewish understanding of planetary days and hours works along the same lines it is further nuanced through the Sefer Yetzirah’s attributions of the Hebrew letters to the seven planets. These are considered to be of primary importance for understanding the mystical influences of each planetary day and hour, though they do go along with along with the astrological attributions discussed above.
However the planetary hours are not just to determine the general influences present during one’s magical work. This, in fact, is a secondary attribute of the system. Their primary purpose is for determining the best time for magical and spiritual workings. For instance, using the letter-to-planet chart we see that work relating to the gaining of wisdom are best done on the day and hour of Saturn while work relating to the increase of wealth or love is best best done on the day and hour of Jupiter. It is also possible to work out the best timing for complex workings that may combine two different features, such as gaining wisdom concerning health. In this instance one might decide to perform their work on the day of Saturn and the hour of the sun. It should be remembered that the planetary days and hours are, in many ways, symbolic in nature. The day-to-planet correlations are, ultimately, arbitrary and thus, like the symbols of magical ritual and magical thought, are part of an overall magical language.
