Interactive Free Birth Chart Calculator


Disclaimer and privacy assurance

The birth time tool on this page is for entertainment purposes only, with no warranty expressed or implied. No data from use of the tool is transmitted, saved or used for any purpose.


The Signs of the Zodiac

As serious astrologers have done for centuries, first divide the year into its seasonal quarters. The beginning of each season is indicated by the onset of Winter and Summer Equinoxes and Solstices.

Second step is to sub-divide the four seasons into middle and end, making twelve signs in total. Each sign lasts for approximately one month.

Four Cardinal Signs (beginning of the four seasons)

Representing the beginning of either an Equinox or a Solstice: Aries ♈ Cancer ♋ Libra ♎ and Capricorn ♑.

Four Fixed Signs (middle of the four seasons)

After a Cardinal sign ends is the middle of the season: Taurus ♉ Leo ♌ Scorpio ♏ and Aquarius ♒

Four Mutable Signs (end of the four seasons)

Heralding the end month of each season: Gemini ♊ Virgo ♍ Sagittarius ♐ and Pisces ♓

Astrology and Cyclical Time

Is astrology just superstitious nonsense?

There is a serious and a frivolous side to many subjects including astrology. To the modern astrologer the subject concerns cyclical time and its effects on sociological consciousness.

To the ancients astrology concerned colossal and fateful activities of the gods, with fateful outcomes over which we have no control.

Do planets match the seasons?

Mars doesn't synchronise with Earthly seasons, so why does it share zodiacal attributions? Although sun signs do correspond precisely with seasons on earth, the astronomical fact behind this is the ecliptic longitude of the Earth's orbit.

Every system needs a zero-point for calibration and measurement, and still today, astronomers and astrologers, both, use the moment of vernal equinox as longitude zero for every object in space.

To illustrate the zodiacal system, imagine each planet as an actor with his/her personality given by the length of planetary year.

Saturn is oldest, Mercury is youngest, and each zodiac sign as the stage in which is currently playing.

Each planetary year then becomes a literary metaphor for a whole life or career, and each zodiac sign then becomes a way-point on your own journey.

Your birth time signifies a starting configuration, with the full expectation of experiencing every stage. An astrologer who knows the symbolic attributions of the zodiac and planets can use your chart to generate consistent narrative that can help you understand the idea of a genuine progress or even pilgrimage through life.

Without such guidance our old age will tend to sneak up on us in a terrifying manner. Astrology has remained in use not by being scientifically consistent, but by being symbolically helpful.

Vernal (Spring) Equinox

At the precise moment when day length equals night length, a notional line of extension is projected from the centre of Earth out through the Prime Meridian at Greenwich to strike the zodiacal belt at the exact start of a notional sign of Aries.

This was an observed longitude, nominated as longitude zero in the year 2000. In 2050 another survey will replace this system with a new scientific observation. All calculations for planetary positions other than in these officially observed years are based on maths/physical modelling.

The constellations have changed

The astronomical fact is that the line of the Vernal Equinox does not cross the constellation of Aries as it once did in Babylonian times. This is a common source of confusion. It needn't be, astrologers are only concerned with stars in the same way that clock time is measured by numbers circling around a clock face.

There are no plausible theories of a 'star effect' when it comes to astrology. The magick relates to the period of planetary orbit and applied seasonal poignancy, not to the backdrop decoration given by the constellations. We sort of pretend the Earth is still aligned as it was when the system was first devised. In technical terms we 'correct for precession' so that our observations remain consistently grounded by the temporal fact of our Earthly seasons.

Clocks and Time Tools

Our creative collection

Portal to all articles
Day and Night Map
Converters by Region
All Time Tools