While it may seem like they are in a random order, it is actually a somewhat complicated formula.  Each day is divided into 24 hours.  This is determined by the time from Sunrise to Sunset divided by 12, and the time from Sunset to the following Sunrise divided by 12.  The planetary rulers of each hour follow the  Chaldean order.  This is the order of the planets from Saturn to Moon according to their increasing average daily motion.  Chaldean order of the planets is: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon.  Therefore, Saturn's hour is followed by Jupiter's hour and so on.

The planetary rulers for the days are determined by what planet rules the hour of Sunrise.  In planetary rulerships, a day is not Midnight until the following Midnight.  A day is Sunrise until the following Sunrise.  Each day, we cycle through the 7 planets used three times each, and then the first three planets in another cycle for a total of 24 hours (a threefold cycle).  The next planet in order is the ruler of the Sunrise hour for the following day, and therefore the ruler of the following day.  

As an example: Saturday begins with Saturn ruling the hour of Sunrise.  Hours 1(Sunrise) - 7 takes us through a complete Chaldean cycle.  Hours 8 - 14 and 15 - 21 completes 2 more cycles in the Chaldean order.  That leaves Saturn ruling the 22nd hour, Jupiter ruling the 23rd hour, and Mars ruling the 24th hour.  That completes Saturday, and brings us to the first hour of the following day.  It is ruled by the next planet in the Chaldean order, the Sun.  Because the ruler of the Sunrise hour becomes the ruler of that day, the Sun's day (Sunday) follows Saturn's day (Saturday).  This continues in an unending pattern, giving us the daily ruler that our weekdays were named after.



This is one of the most basic applications of astrology.  The energy of the planet ruling the day is increased on that day.  Likewise, the energy of the planet ruling the hour is stronger during that hour.  This gives astrologers deeper insight into the influences of a specific time.  It is also a way to select a time (in electional astrology) with more appropriate energies even if the ruling planets aren't strongly aspected.  You will have strong Mars energy during Mars hour on a Tuesday, even with a weak Mars placement.  This can also be used for combinations of planetary energy.  For example, if you are planning a date Mars - Venus is a classic romantic combination. Try a Mars hour on Venus day - this is always easy to determine, Mars rules Sunset and the following hour on Friday evenings!

The use of planetary hours and days can be applied, even by non-astrologers.  Our planetary hour charts have a keyword guide at the bottom of each page.  When planning any activity, choose a combination of hour/day with ruling planets whose energy seems appropriate for a more successful outcome.  This method has long been used by gardeners and herbalists.  Planting as well as harvesting can be more productive if you choose the hour/day of the planet ruling the specific plant in question.  This method, combined with Moon phases, and Moon signs can give you amazing results!  For herbs, harvest during the hour ruled by the planet reflecting the intended use of that herb.

There is an unlimited amount of uses for this method in spiritual matters.  Meditation and chakra work can be greatly enhanced this way.  See our chart of planetary rulers of the chakra.  Whatever chakra is ruled by the planet who is ruling the current day or hour is more active.  For Wiccans and Pagans, use of planetary hours and days is quite traditional.  The most effective spells and rituals are performed on the appropriate day, at the appropriate hour.  Some consider this as important as the Moon's sign.  Anything you make yourself such as incense, magickal waters, amulets, talismans and so on can be given added strength by choosing the best time to make them.