When individuals share the same birth date, it is known as a “birthday twin” or “birthday buddy.” This phenomenon occurs with surprising frequency due to the combined effects of the Poisson distribution and the law of large numbers. The birthday paradox, which states that in a group of 23 people, there is a 50% chance of at least two people having the same birthday, is a well-known example of this phenomenon. Birthday совпадения and other birthday phenomena have fascinated individuals throughout history and have been explored in various fields, including mathematics, psychology, and sociology.