A cusp occurs when a person is born on a date in between two signs (usually the 20th-23rd). However the cusp does not mean the person will display the traits of both signs just because they are born on that day. All of the signs are based off degrees rather than a continuos spectrum. For example, if a person is born on the 21st of June they do not have both traits of Cancer and Leo. Depending on their birth time they will either have degrees close to thirty in Cancer or degrees close to one in Leo; each sign has a maximum of thirty degrees (30 degrees per sign x 12 signs = 360 degrees total). To truly know your sun sign when born on a cusp you must know your birth time to get the exact degree of the sign.
There have been rumors of having both traits when you are born on a cusp, however it would be impossible because of the degree system. If you have any questions do not hesitate to comment below :)
