The ancients only knew of seven planets. These were the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. The other planets were not discovered until the invention of the telescope. These planets and their energies were attributed to the days of the week and the hours of the day.
Just as there are seven planets, there are seven days of the week. The Sun is attributed to Sunday. The Moon is attributed to Monday. Tuesday is attributed to Mars. Wednesday is attributed to Mercury. Thursday is the day of Jupiter. Friday is the day of Venus. Finally, Saturday is the day of Saturn.
For the ancients, the day started at sunrise and ended at sunset. The night, therefore, went from sunset to sunrise. During both the day and the night there are twelve hours. These hours may be longer or shorter than our normal 60 minute hour. For example, daytime hours are longer than nighttime hours from the Spring equinox to the Fall. During this time, the daytime magical hours will probably be longer than 60 minutes each, and the night time hours shorter than 60 minutes. The reverse would be true from the Fall equinox to the Spring.
To compute the magical hours for any day in question, all you need to know is the sunrise and sunset times. From this, you can compute the length of daytime hours. You can find this information at http://www.sunrisesunset.com/ .For example, on the day I am writing this, where I live the sun rises at 6:17 AM and sets at 8:21 PM. So, this tells me that the length of the day is 14 hours and 4 minutes. To convert this into magical hours, first figure out the number of minutes total in the day. 14 hours times 60 minutes gives 840 minutes, plus the extra four minutes gives a total of 844 minutes for the day. Then, since there are 12 magical hours in the day, you divide 844 by 12 to get 70 minutes. Therefore, each of the daytime hours is 70 minutes.
In our normal time, two hours equals 120 minutes. So, the total of one daytime hour and one nighttime hour must equal 120 minutes. So, to find the length of the night time hours you subtract the number of minutes in one daytime hour from 120 and this will give you the number of minutes in one night hour. In our example, you would subtract 70 from 120 to get 50. Therefore, there would be 50 minutes in one night time hour.
Now that you have the number of day and night minutes in each hour, you need to find what planet is assigned to which hour. This is easy to do. The order of the planets for this is: Sun, Venus, Mercury, Moon, Saturn, Jupiter, Mars. You do not have to memorize a whole chart. Just this order of the planets. To determine the hours, the first hour of the day is always attributed to the same planet as the day. So, for example, today is Wednesday, which is Mercury. Therefore, the first hour of the day, from 6:17 AM to 7:27 AM, is also Mercury. From there, just follow the order. The second hour is the Moon, the third is Saturn, the fourth is Jupiter, the fifth is Mars, the sixth is the Sun, the seventh is Venus, the eighth is Mercury, and so on. This order continues through the night. The twelfth hour of the day is Mars, so the first hour of the night would be Sun, and the pattern continues.
When doing a magical working, the actual work done should be conducted during the appropriate magical hour. The opening and closing of a circle or temple may be before or after the hour, but when working with the energies of a particular planet the work should be on the appropriate hour.