If you were born between the 19th and 23rd of any month, you may have been told that you were born on the cusp. That is true.
However, you do not automatically have two sun signs. Here is an explanation.
The Sun’s apparent path through the zodiac takes about 12 months. Those 12 months coincide with our 12-month calendar year, almost exactly. Our calendar months do not coincide precisely with the actual celestial month. We are out of sync by a little bit of time (that is why we have Leap Years).
To put it another way: our calendar year is a little bit shorter than the Sun’s traveling year.
This means that the Sun moves into a new zodiac sign approximately every month, anywhere between 19th and the 23rd of our month.
For example, one year the Sun can change signs on the 22nd, and another year it may change signs on the 20th.
The change can happen on any day between the 19th and the 23rd. That group of days is called a cusp, meaning the span of days in which the Sun may change sign.
The cusp does not mean that the sun is in both signs during those days.
The cusp means that the Sun will change signs on one of those days.
The Change is Fast
And that change will happen very fast, over the course of a minute or so. This is because we consider the Sun being in a sign when its center is in a sign. For example, when we say the Sun is in Taurus, it means the center of the sun is in Taurus.
If you were “born on the cusp” of two signs, it really means that at the exact moment you were born, the sun was either in the previous sign, or in the next sign. It is unlikely that you were born at the same moment in which the center of the sun was exactly between two signs.
So, being born during those cusp days does not automatically mean that you have two Sun signs.
Birth charts are calculated using an astronomical ephemeris in order to get the exact time that the Sun changed signs for every month of every year. An ephemeris is a special almanac that gives the astronomical positions of celestial objects. It shows the exact positions of the center of the Sun for every day of every year.
If you were born between the 19th and 23rd of any month, you must check an ephemeris to see exactly where the Sun was at the time of your birth. Or use our Sun Sign Calculator which has a built-in ephemeris to get exact positions.
Earlier Cusp For February Births
However, if you were born in February, the cusp begins earlier, as early as the 17th day. That means that if you were born between February 17th and 21st, you must check an ephermis or use our calculator to see exactly what sign the sun was in when you were born.
Alternate Meaning of Cusp
There is a second meaning for "cusp" in astrology, but it is not important for this discussion. The second meaning refers to the cusp between two houses instead of the cusp between two signs.