What is a Cusp?

You may have heard the phrase "on the cusp". What this means is that you are on the edge of a sign. Traditionally, the cut off date between signs is the 21st of the month. For example, to be a Leo you would be born between July 21 and August 20. July 20th would be a Cancer and August 21 would be a Virgo.

However, for the first few days before and after the 21st you would be considered on the cusp. This means you are likely to have characteristics of the sign on the other side of the cut off day. In the above example, while someone born on July 20th would be a Cancer, they are highly likely to have Leo tendencies.

There are several reasons for this. First astrology is about the change of the seasons and stars of life. It is about gradations of difference. So things move from sign to sign incrementally and these slow movement show up in the changes and overlap from sign to sign. The second reason for the cusp concept is that our calendar is not perfectly aligned with the stars. So the signs change based on the movement of the heavens does not actually happen on the 21st every month. If you want an accurate representation of the stars on the day of your birth you would need to refer to an ephemeris for exact information or have your natal chart done.

Without going thru this level of detail its just good to remember there is a lot of change and fluctuation around the edges of the signs.