What is the Sun Sign, and Why It is Important

The Sun Sign, aka "the Star Sign" is well known to most people thanks to the popular "horoscopes". In most cases, you can easily find it out from your date of birth. Here is a typical arrangement of dates for all the twelve Sun Signs:

Aries 21 March - 20 April Libra 24 September - 23 October
Taurus 21 April - 21 May Scorpio 24 October - 22 November
Gemini 22 May - 21 June Sagittarius 23 November - 21 December
Cancer 22 June - 22 July Capricorn 22 December - 20 January
Leo 23 July - 22 August Aquarius 21 January - 19 February
Virgo 23 August - 23 September Pisces 20 February - 20 March

Astronomically, the Sun Sign is the sign of the zodiac in which the Sun was situated at the moment of the person's birth.

Why the Sun Sign is Important

The Sun Sign is a major astrological parameter for a person, and so it can be more or less important for different people depending on how much attention they are paying to astrology in their lives. However, when it comes to finding out the level of luck on a particular day, the Sun Sign becomes very important as most simplified approaches to calculating the level of luck take the Sun Sign in consideration.

This makes a lot of sense. From what we know about good luck now, it seems that a person is more lucky when he or she is following the path that is offered to him or her in the current incarnation. So the simplest possible answer to the question "how to be lucky?" is "just be yourself".

However, this isn't such an easy answer as it seems to be. What does it mean to be oneself? What did we come to achieve or to create in this life? The Sun Sign is an important component of the answer to all such questions, and this is why knowing one's Sun Sign can be really important.

What is the Problem Then?

For most people, finding out their Sun Sign is easy, and the table above is everything they need.

However, if a person was born close to the border between two signs, finding out his or her Sun Sign can be more difficult. The Sun's movement across the sky isn't perfectly aligned with the human calendar, it enters any next sign of the zodiac at a particular moment in time, each year this moment is different and in different locations around the Earth it will map to different local times.

Claire Doyle-Beland has partially understood the problem, and in her book she offers different dates for Sun Signs for different years. This isn't an adequate solution though as the Sun doesn't enter the signs of the zodiac at midnight, it can do it at any moment during the day. And even if it happened on some year to enter a sign exactly at midnight, New York time, that same moment wouldn't be midnight in, say, Tokyo.

Let's consider a detailed example to better understand the problem.

In 1980, the Sun entered the Sign of Aquarius on the 20th of January, at 21:49 (9:49pm) Greenwich Mean Time (GMT). This means that of all those people born in London, if they were born on the 20th of January before 9:49pm, their Sun Sign was Capricorn, but after that moment it was Aquarius.

In New York, the very same moment was 4:49pm local time. So, despite what you see in the general table above, those born in New York after 4:49pm on the 20th of January 1980 were Aquarians, not Capricorns. And in San Francisco, the border between the two signs was crossed at 1:49pm. Can you see the problem?

Now, if we take the next 1981 year, the Sun has crossed the border between Capricorn and Aquarius on the 20th of January at 3:37 (3:37am) GMT. That's 7:37pm of the 19th of January in San Francisco! So in San Francisco everyone born on January the 20th, 1980, and a significant part of those born on January the 19th, had Aquarius for their Sun Sign, not Capricorn, despite what the general table says.

Okay, but is there any way then to find out a person's true Sun Sign in border cases? Yes, there is. There are, actually, a few different ways of varying complexity, you can select the one which is the most convenient for you.

How to Find Out a Person's Sun Sign in Border Cases?

First of all, you need to know the time and the place of birth. The more precisely you know the time of birth the better. If you know the time only approximately, like "in the morning", or "at night", make some reasonable approximation. Or, if you don't know the time of birth at all, take the local noon in the place of birth, to minimize the error.

To find out the true Sun Sign, you have the following options:

Sun Sign Calculator and Its Limitations

My online Sun Sign Calculator is quite precise, it uses a state-of-the-art astronomical algorithm, but its limitation is that it relies on the definitions of the time zones provided by the computing platform it is built upon.

Those time zones provided by the computing platform are good enough for most countries for the last few decades, they take in consideration Daylight Saving Time and other changes. However, the history of time zones around the globe is too complicated, and the widely available time zone definitions don't take into account all the peculiarities of that history. For example, they don't reflect the fact that in the 1950s no Daylight Saving Time was used in Florida, and so depending on the date and time of birth the Sun Sign Calculator might produce a wrong result.

Also, some countries, like Russia, keep changing their time zones every now and then. It will take a while before those changes will be reflected by software platforms around the world, and so the Sun Sign Calculator won't be reliable for those born in the last few years in Russia.

If there is any reason why you believe the Sun Sign Calculator might not work well for you, consider the other available options.

Using Online Natal Chart Calculator

A complete astrological chart is a schematic picture of the sky at the moment of birth, and it has all the details in it, including the precise position of the Sun in a sign of the zodiac. Previously, you had to purchase an expensive software to calculate such a chart, or to do all the nontrivial calculations yourself using various tables, but nowadays there are free online services that can calculate a precise horoscope for you.

These services are more precise than the Sun Sign Calculator mentioned above because they usually make use of the ACS Atlas, the best available knowledge base regarding geographical locations and their time zones. As a result, a birth chart created by an online service will give a more precise information about the Sun Sign than the Sun Sign Calculator for those born more than a few decades ago.

However, take into account that depending on how recently a particular copy of the ACS Atlas was updated, online services might not have the most up-to-date time zone changes for some countries.

Once you have your natal chart calculated, find the Sun and its zodiacal position among various other details. For this, you'll probably need to know the astrological symbols for the Sun and for the signs of the zodiac.

There are other online horoscope calculation services which you can use as well, here is a couple of them:

Doing It by Hand

To find an exact moment when the Sun enters a sign, you can use one of the available Ephemeris books, such as The American Ephemeris, or freely available online ephemeris in PDF format at Astro.com website. To find the most precise available information about time zones and time changes around the world, you can use The American Atlas or The International Atlas published by ACS Publications.

Then it's just a matter of simple arithmetical calculations, to figure out whether a person was born before the Sun has changed the sign or after that.

If you need more information on this, please let me know.

© 2021 Alexander Kolesnikov