The Book That Knows You Better Than You Know Yourself?
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A Deep Dive into The Power of Birthdays, Stars & Numbers
Hey everyone! Welcome back to the blog. If you’ve been following me for a while, you know that I am absolutely obsessed with the tools we use to decode the universe. Whether it’s the vibration of a number or the transit of a planet, I believe everything is a clue to who we are.
Today, I’m pulling a heavy hitter off my bookshelf. I’m talking about “The Power of Birthdays, Stars & Numbers: The Complete Personology Reference Guide” by Saffi Crawford and Geraldine Sullivan.
If you are into metaphysics, you’ve probably seen this book. It’s huge, it’s comprehensive, and it promises a lot. But does it actually deliver? As a professional numerologist, I’m always a little skeptical when I see a book trying to do everything at once. Can you really mix astrology, numerology, and fixed stars without watering them all down?
I sat down with this 800-page beast to give you my honest, expert opinion. I’m going to break down how they handle the math, where they get the astrology right (and wrong), and why I think this might be one of the most important reference books you can own—even if I have a few major gripes with it.
So, grab your tea (or your calculator), and let’s dive in.
The “Holistic” Numerology: A New Spin on Old Math?
Let’s start with my bread and butter: the Numerology.
The authors, Crawford and Sullivan, have made a really interesting choice here. They use the Pythagorean system—which is the standard Western method most of us use—but they’ve tweaked the branding in a way that I find both clever and a little confusing.
The “Holistic Number”
If you open this book looking for your “Life Path Number,” you might think you picked up the wrong text. The authors don’t use that term. Instead, they call it the Holistic Number.
They calculate it the same way we calculate a Life Path (adding up the Month + Day + Year of birth and reducing it to a single digit). For example, if you were born on November 11, 1975, they walk you through the math to find that your Holistic Number is 8.
I actually kind of love the term “Holistic Number.” It implies that this number is the sum of your parts, the container that holds your entire journey. They describe it as the number that reveals your life purpose and the central mission your soul has chosen. In the daily profiles, they do a great job of weaving this vibration into the personality description. They don’t just say “You are a Scorpio.” They say, “You are a Scorpio with a 4 vibration,” and then explain how that 4 energy (stability, hard work) grounds the intense emotional water of Scorpio.
The Personal Year
One of the absolute best features for numerology fans in this book is the inclusion of the Personal Year Number. Most birthday books are static—they tell you who you are, but they don’t tell you where you are going.
Crawford and Sullivan include a whole section on forecasting. They teach you how to calculate what year cycle you are currently in (1 through 9). This transforms the book from a one-time read into a tool you can use every New Year’s Eve. If you’re feeling stuck and sluggish, checking this book and realizing you’re in a “7 Year” (a year for introspection and rest, not major action) can be such a relief. It validates the natural rhythms of your life. 1
Astrology: More Than Just Sun Signs
Now, let’s talk about the Astrology. If you’re expecting generic “Leos are loud, Cancers are crybabies” stuff, you’re going to be pleasantly surprised. This book respects the complexity of the zodiac in a way that most pop-astrology books don’t.
The Decanate System
The biggest “pro” here is their use of Decanates (or decans).
Here’s the quick lesson: Every zodiac sign spans 30 degrees of the sky. But a Scorpio born on October 24th is mathematically different from a Scorpio born on November 20th. The authors break each sign down into three 10-degree chunks.
- First Decan: Ruled purely by the sign itself.
- Second Decan: Influenced by the next sign of the same element.
- Third Decan: Influenced by the last sign of the same element.
In the book, they use these sub-rulers to explain nuance. They explain why an early Aries might be pure fire and aggression (ruled by Mars), while a later Aries might have a bit more shine and ego (ruled by the Sun/Leo influence). This is real, technical astrology presented in a way that doesn’t feel like a textbook. It explains the “flavor” of your specific birthday, not just your general month.
The Secret Sauce: Fixed Stars
Okay, this is the part that makes me geek out. This is the feature that bumps this book up from “Good” to “Essential.”
The Fixed Stars.
In modern Western astrology, we focus heavily on the planets in our solar system (Mars, Venus, Jupiter, etc.). But ancient astrologers were obsessed with the stars behind the planets—the constellations. This book assigns a specific Fixed Star to every single birthday. 2
This is rare. You usually have to pay for a specialized reading to get this info. The authors explain that because the Fixed Stars move so slowly (one degree every 72 years), they stay consistent for generations.
For each birthday, they tell you which star was aligned with the Sun.
- Born near Regulus? You might have a destiny involving high honors or public leadership.
- Born near Sirius? You have a blazing intensity and a spiritual mission.
- Born near Algol? You might deal with some intense, passionate, and transformative energy.
They provide the name of the star, its constellation, and its mythological meaning. For me, this adds a layer of “destiny” that simple numerology or sun signs miss. It connects you to the galactic history of the sky. If you’ve ever felt like your horoscope didn’t quite fit, it might be because a massive Fixed Star is overriding your Sun sign—and this book is one of the few that will tell you that. 4
Is It Still Relevant Today?
This book was published in the late 90s (1998 to be exact), so you might be wondering: Is it outdated?
Honestly? It’s more relevant now than it was then.
We are currently living in a massive revival of “New Age” thinking. People on TikTok and Instagram are talking about “Starseeds,” “Galactic Origins,” and “Shadow Work.” This book was doing that twenty-five years ago.
The “Secret Self”
One of my favorite sections in every profile is called “Your Secret Self.”
This isn’t about your career or who you should date. This section digs into your psychology. It talks about your hidden fears, your subconscious motivations, and the parts of yourself you try to hide from the world.
In today’s climate, where everyone is obsessed with therapy and self-knowledge, this section hits hard. It feels less like fortune-telling and more like psychoanalysis. For a November 11th birthday, for example, it talks about the tension between wanting to save the world and being too hard on yourself—a very specific psychological struggle that goes beyond just saying “You’re a Number 11.” 6
Where I Disagree (The Numerologist’s Gripe)
Okay, I promised I would be honest. I can’t give this book a perfect score, and here is why.
As a numerologist, I find the title The Power of Birthdays, Stars & Numbers to be a little misleading. Yes, they use numbers. Yes, they calculate the Life Path (Holistic Number). But they completely leave out Name Numerology.
In a complete numerology chart, your Birth Date is your “Life Path” (what you are here to do), but your Name is your “Expression” (how you do it). Two people born on the same day might have the same “Holistic Number,” but if one is named “Elizabeth” and the other is named “Zoey,” they are going to have drastically different personalities and tools at their disposal.
The authors barely touch on this. They focus almost exclusively on the date. By ignoring the name, they are missing 50% of the numerological picture. They treat the “Number” part of the book as a modifier to the Astrology, rather than a standalone system.
If you rely only on this book for your numerology, you are missing out on the “Soul Urge,” the “Expression Number,” and the “Personality Number”—all of which are derived from your name. It’s a “Personology” book, not a Numerology textbook. It’s a hybrid system. That’s fine, but as a purist, I have to point out that it’s not the whole math.
Other Topics & Cool Features
Before we wrap up, there are a few other things tucked inside these 800 pages that are worth mentioning:
- Progressed Sun Cycles: This is super advanced for a pop-book. They actually tell you when your “Progressed Sun” changes signs. They will say things like, “At age 41, your sun moves into Capricorn, and you will become more serious about your career.” This is an incredible tool for understanding mid-life changes. 6
- Famous Birthdays: It’s just fun. It lists tons of celebrities and historical figures born on your day. It’s a great way to see the “archetype” in action.
- Relationship Guide: They give advice on who you get along with, not just by sign, but by specific birthdays. It’s a little fatalistic sometimes, but very detailed.
The Verdict
So, should you buy it?
If you are looking for a coffee table book that you will actually read, yes. If you want to understand why you and your “Time Twin” (someone born on your same day) are so similar, this is the bible for that.
It’s comprehensive, it’s beautifully written, and the inclusion of the Fixed Stars makes it unique in a crowded market. It bridges the gap between the fluff of newspaper horoscopes and the density of academic astrology.
However, if you are looking to become a professional numerologist, you will need supplemental books to learn about Name Numerology. This book won’t teach you that.
But for what it is—a “Complete Personology Reference Guide”—it is a masterpiece of synthesis. It weaves three complex systems into a profile that feels eerily accurate. It feels like the authors are sitting right in front of you, reading your soul.
My Rating: 4.5 out of 5 Stars
(I knocked off that half-star for the missing Name Numerology! Sorry, I had to!)
Where to Buy:
You can grab your copy of The Power of Birthdays, Stars & Numbers right here on Amazon now!