Calculating Planetary Hours

Each hour of the day and night is ruled by a different planet. Each hour, therefore, takes on the energy and aspects of that planet, tempered by the day of the week. Below are some simple directions for determining the planetary hour for any given day, for the daylight hours. If you wish to determine the planetary hours for the night, use the sunset time of the first day and the sunrise time of the following day.

  1. Find the sunrise and sunset times for your location for the day in question. You can usually find these on a weather website or in your local newspaper.
  2. Convert the sunset time into military time. The easiest way to do this is to add 12 hours. For example, 5:52 pm becomes 17:52.
  3. Convert the hours into minutes for both the sunrise and sunset times. Do this by multiplying the hour by 60 and adding the minutes. For example: 5:15 am becomes 5*60+15=315.
  4. Determine the hours of daylight by subtracting the sunset minutes from the sunrise minutes.
  5. Determine the length of each planetary hour by dividing the result by 12.
  6. Consult the chart below to see which planet the first hour belongs to, the second, and so on. It may be helpful to write out the times of each planetary hour. (See the example below.)

Here’s an example using the sunrise and sunset times for July 31, 2003 for London, Ontario, Canada.

  • sunrise: 6:14 am => minutes = 6 * 60 + 14 = 374
  • sunset: 8:48 pm => convert to 24h time = 12 + 8 = 20:48 => minutes = 20 * 60 + 48 = 1248
  • hours of daylight = 1248 – 374 = 874
  • lenght of planetary hours = 874/12 = approx. 1 hour 13 minutes
  • So the first planetary hour for today would be 6:14 – 7:27, the second would be 7:27 – 8:40, etc.
  • Now look at the chart for Thursday to determine which planet corresponds to which hour.

If all these calculations are a bit much, you can go to this site to have the hours calculated for you. Personally, I am of the opinion that it is better to do it yourself, and it shouldn’t be so much extra work since you have put so much research into your ritual already, right?