Astrological "birthday cousins" are more in line with numerology, but they sometimes explain why some signs do/don't get along with each other when they seem to go against standard presumptions. It's based on the total number value of the birthday itself--so in cases when an individual with an apparent inconjunct/quincunx that might indicate a stress pattern of interaction DOES find a social-emotional-physical connection with a partner, this might explain it. You should know your range of inconjunct planets. I'm not saying these are exclusive, and for sure, some folks do not engage well with their squaring planets, and even opposition planets. This is just a possibility idea of mine.
To start, take the single number value of the birthdate itself. For example, a "14" is minimized to 1+4 = 5. The same for a "23" as a total value of 5. Anyone born on any three of those dates (5, 14, 23) are "astrological cousins". Similarly, a person born on the 1st would be in synch with a person born on the 10th, 19th, and 28th. Only 11/29 have their dual pairing.
Only one birthday is not reduced: the Master Birthday 22. These individuals are unique in their own way: they have a singularity of focus that is both powerful and specialized (said to be either a spiritual-religious or a financial/materialistic goal in mind). A connection with another 22 birthday would be very intense.
