A platinum birthday is a special birthday celebration that occurs when a person turns the age that matches the last two digits of their birth year. For example, if someone was born in 1999, their platinum birthday would be when they turn 99 years old. However, there is another definition of a platinum birthday that has become popular on TikTok. According to this trend, a platinum birthday is the day when a person turns the age that corresponds with the day they were born, but flipped. For instance, if someone was born on the 12th day of the month, their platinum birthday would be when they turn 21.

It is important to note that there is some confusion around the definition of a platinum birthday, and different sources provide different explanations. Some people believe that a platinum birthday is the year when a person turns the same age as their birth year, while others think it is the year when a person turns the age that corresponds with their birth date.

In summary, a platinum birthday is a special birthday celebration that occurs when a person turns the age that matches the last two digits of their birth year. However, there is another definition of a platinum birthday that has become popular on TikTok, which refers to the day when a person turns the age that corresponds with the day they were born, but flipped.