The planetary hours are hours of the day in which each planet holds influence. The way that one calculates it is to take the time of daylight or night time and divide by 12.
Now, this seems simple enough to start with, however it gets a bit complicated when you factor in day light is less than 12 hours, as is night time. You need to know the exact time of the sunrise and sunset to calculate the day light hours.
So, if sunrise is at 7:20am and sunset is at 5:20pm, you have 10 hours of day. Divided by 12 that gives you 0.833 hours for each planet. Multiply that by 60 minutes and you get 50 minutes per daylight hour.
If sunset is 5:20pm and sunrise is 7:20am, you have 14 hours of night. Divide by 12 that gives you 1.1666 hours for each planet. Multiply that by 60 minutes and you get 70 minutes per night time hour.
Easy enough once you get the hang of it. Now we complicate matters. The hours of the planets change with the day or night of the week. Here are the tables:
Planetary Hours of the Day
Hour
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
1
Sun
Moon
Mars
Mercury
Jupiter
Venus
Saturn
2
Venus
Saturn
Sun
Moon
Mars
Mercury
Jupiter
3
Mercury
Jupiter
Venus
Saturn
Sun
Moon
Mars
4
Moon
Mars
Mercury
Jupiter
Venus
Saturn
Sun
5
Saturn
Sun
Moon
Mars
Mercury
Jupiter
Venus
6
Jupiter
Venus
Saturn
Sun
Moon
Mars
Mercury
7
Mars
Mercury
Jupiter
Venus
Saturn
Sun
Moon
8
Sun
Moon
Mars
Mercury
Jupiter
Venus
Saturn
9
Venus
Saturn
Sun
Moon
Mars
Mercury
Jupiter
10
Mercury
Jupiter
Venus
Saturn
Sun
Moon
Mars
11
Moon
Mars
Mercury
Jupiter
Venus
Saturn
Sun
12
Saturn
Sun
Moon
Mars
Mercury
Jupiter
Venus
Planetary Hours of the Night
Hours
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
1
Jupiter
Venus
Saturn
Sun
Moon
Mars
Mercury
2
Mars
Mercury
Jupiter
Venus
Saturn
Sun
Moon
3
Sun
Moon
Mars
Mercury
Jupiter
Venus
Saturn
4
Venus
Saturn
Sun
Moon
Mars
Mercury
Jupiter
5
Mercury
Jupiter
Venus
Saturn
Sun
Moon
Mars
6
Moon
Mars
Mercury
Jupiter
Venus
Saturn
Sun
7
Saturn
Sun
Moon
Mars
Mercury
Jupiter
Venus
8
Jupiter
Venus
Saturn
Sun
Moon
Mars
Mercury
9
Mars
Mercury
Jupiter
Venus
Saturn
Sun
Moon
10
Sun
Moon
Mars
Mercury
Jupiter
Venus
Saturn
11
Venus
Saturn
Sun
Moon
Mars
Mercury
Jupiter
12
Mercury
Jupiter
Venus
Saturn
Sun
Moon
Mars
http://www.renaissanceastrology.com/planetaryhoursarticle.html
Correspondence of Days of the Week
(day; planet; color; diety; intent)
Monday Moon Silver, white, blue Diana, Artemis, Selene, Luna women's mysteries, illusion, glamour, sleep, peace, beauty, prophesy, dreams, emotions, travel, fertility, insight, wisdom
Sunday Sun gold, yellow Brigid, Helios, Apollo success, promotion, fame, wealth, prosperity
http://www.witchipedia.com/table:days-of-the-week
To work with Saturn on a Tuesday morning, you will need to determine the length of your ?day?, calculate the length of a planetary hour and multiply by six, then add this to the time of sunrise to find your time to work with Saturn that Tuesday. Going with the above figures, that comes out to about 1:20 pm to 2:10 pm. To work with Saturn on a Tuesday night, you will need to do the same as for the day, making the optimum time 5:20 pm to 6:30 pm.
This can be a great way to fine tune a spell or ritual for a specific matter. Consider the moon phase and time of year will help as well. Subtle things like this can make a massive difference in the results of a spell or ritual. Now, if you cannot wait for the optimal time, don?t worry. You can do the spell at any time and still get great results. Use as many of these factors as you can in the work. Make use of other correspondences to aid a bit of oomph to the spell.