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How to Use Decennials in Astrology

Decennials are one of the many wonderful ancient Hellenistic Astrology predictive techniques rediscovered during Project Hindsight by Robert Schmidt and others in the early ‘90s, and is similar to Firdaria or Zodiacal Releasing in which your life is broken down into chapters.

It divides your life into 7 different periods, of 10 years and 9 months each, each of which is governed by one of the 7 Classical Planets. The first period starts with the sect light, which is the Sun for diurnal charts and Moon for nocturnal charts.

Continue reading for more details:

Astrological Decennials

Using decennials is a useful way to gauge what chapter in life you are currently in and what the overall flavour may be based on the ruling Planet. It is particularly useful when used in conjunction with other, shorter, timing techniques such as Annual Profections, Solar Returns, or transits to paint a more detailed picture.

It can also be used with other, longer, timing techniques such as Firdaria and Zodiacal Releasing to act as different layers on the background of your painting.

When we are forecasting in Astrology we are looking for repeating patterns. If one technique points to an occurrence, we may take note; but if three different techniques seem to reiterate a similar theme, then we pay stronger attention.

Or if the ruler of your Solar Return Ascendant is the same Planet as your decennial sub-period, you would pay extra attention to tracking its transits! It is a great way to control the directions of your focus and energy.

Why does each Planetary decennial chapter last 10.9 years? The sum of the so-called “lesser years” of the Planets is 129 (which is how long its takes them to complete a synodic cycle, i.e. return back to the exact same degree in the Zodiac with the Sun). The sum of 10 years and 9 months is 129 months. Thus, decennials act like a mirror or microcosm of the larger cycle.

According to 2nd Century Astrologer Vettius Valens, these are the minor years:

Saturn – 30 (we complete our first Saturn Return around 30)
Jupiter – 12 (Jupiter also takes 12 years to cycle through the Zodiac)
Mars – 15 (every 15 years it retogrades in the same place)
Sun – 19 (the Sun and Moon meet for a New Moon or Full Moon in the same position every 19 years, i.e. the “metonic” or eclipse cycle)
Venus – 8 (every 8 years Venus retrogrades in the same Sign at the same degree)
Mercury – 20 (there are 63 synodic cycles in 20 years)
Moon – 25 (the relationship between the lunation cycle and the Egyptian 360 day calendar that repeats every 25 years; the time it takes for its phases to reoccur on the same days of the year)

Notable 4th Century Astrologer, Firmicus Maternus, also delineates them in his Mathesis.

After beginning with the Sun or Moon, depending on if you were born in the day or night, the following periods continue with the next Planets in Zodiacal order as they appear in your Natal Chart.

Each period is also divided into 7 sub-periods. The first sub-period belongs to the same Planet as the entire decade, then the order of the sub-periods is determined in the same way as the main periods. The distribution of the months is according to the lesser years of the planets minimised to months instead of years. So Saturn would rule 30 months, Jupiter 12, Mars 15, the Sun 19 months, Venus 8, Mercury 20, and the Moon 25.

Put another way: the first Planet in the cycle starts from the beginning of life until 10 years and 9 months old, then the next Planet is going to rule for another 10 years and 9 months, and so on.

Here is a yearly table breakdown:
1. From birth to 10 years and 9 months old.
2. From 10 years 9 months old, to 21 years 6 months old.
3. From 21.6 years old to 32.3 years old.
4. From 32.3 years old to 43 years old.
5. From 43 years old to 53.9 years old.
6. From 53.9 years old to 64.6 years old.
7. From 64.6 years old to 75.3 years old etc.

Here is a free calculator to do it for you.

two-wander-how-to-use-decennials-in-astrology

How to Interpret your Decennial Period

Like any other technique, you begin with interpreting the Planet by Sign and House and then move onto its ruler and do the same for the sub-period Planet, including any other Houses they rule.

The level 1 time lord (years) is like broad, over-arching themes, the backdrop to your painting; whereas the level 2 time lord adds in detail or focus for those specific months.

Decennial interpretation

For example, let’s say you were born during the day and you are 35 years old, this would put you in your fourth “chapter”. Based on the Natal Chart depicted above, this would be a Moon period.

As we can see from the Chart, the Moon is in Aquarius in the 3rd House of Communication. Aquarius speaks to themes of independence, freedom, community, innovation, and carving a unique path.

The 3rd House speaks to themes of learning (particularly early childhood), social media, divination, craftwork, siblings, aunts, uncles, cousins, mindset, self-expression, writing, and local neighbourhood.

Saturn, the ruler, is domiciled in Capricorn in the 2nd House of Income. This can add themes of building, structure, discipline, tradition, ambition, and striving; and finances, resources, possessions, values, and skills.

Thus we can say this decade may be largely coloured by themes of self-expression, breaking free, local community, and building wealth.

Decennial sub-period

The sub-period ruler is Mars. Mars is Natally domiciled in Scorpio in the 12th House. This can tie in solitude, isolation, mental health, spirituality, long-distance travel, intimacy, depth, psychology, retreat, institutions, subconscious, transformation, the occult, and regeneration.

Mars is also the ruler of the 5th House of Creation which can add in themes of children, creative output, sex and sexuality, fun, romance, hobbies, pleasure, sports, and pastimes.

Thus we can say that within this decade backdrop, for roughly this year, there are additional themes of introspection, privacy, mysticism, and rebirth, coupled with creativity, joy, and children related themes.

So that’s an overview of the decennials in Astrology, I hope it’s insightful for you! Let me know in the comments section below if you have anything else to add or any questions.

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