Calculating Planetary Hours

Each hour of the day and night is also matched to a planetary influence.

• Planetary hours can be very useful, especially if you can’t wait until the right Moon phase or even the right day to perform your magical working. You can, of course, wait for both the appropriate day and planetary hour, if you wish.
• Planetary hours are divided into two parts: sunrise to sunset and sunset to sunrise.
• Planetary hours depend on the date and the location.  

This table presents the rulers of the days of the week and their symbols:

This sequence of the planetary rulers of the days of the week follows the beams of seven-point star, or heptagram, also known as the Star of the Magi:

You don’t need to calculate planetary hours by hand. There is a Planetary Hours Calculator and website that will do the calculation for almost any location and for practically any date. Easy! 

But just in case there is a power outage, here is how you would calculate the planetary our manually.

Manual Calculation of Planetary Hours

Calculating the planetary ‘hours’ once the principle is understood is relatively easy.

The calculation goes back to when there were no clocks to measure time. The periods of light and dark were each divided into 12 equal portions which were called ‘hours’.

Therefore if we divide the number of minutes of daylight by 12, we discover exactly how long a planetary hour is. For example, if the sun rises at 7am and sets at 4pm you would have 9 normal hours of daylight. This would then have to be divided by 12 to calculate when each new planetary hour begins.

Thus:

• 9 hours multiplied by 60 minutes gives 540 minutes
• 540 minutes divided by 12 gives 45 minutes.

Therefore each daytime magical hour would be equivalent to 45 minutes normal time and you would measure accordingly.

From sunset, things would be slightly different – a little thought will show why so many magical practitioners work at night!

Using the example above, we have 15 hours out of 24 left.

Thus:

• 15 hours multiplied by 60 minutes gives 900 minutes
• 900 minutes divided by 12 gives 75 minutes

Each night-time hour would be therefore be equivalent to 75 normal minutes.

Because only the Sun and six planets – not all ten planets – are used as correspondences, you have a chance to use those influences either during the day or during the hours of darkness.

Planetary hours are always calculated with reference to the rising sun, so each time you wish to use a planetary hour, you must first know precisely when the sun rises where you are living.

The influence can either help or hinder our magical efforts.