Given a short bio of a person, find the minimal text span containing the date of birth of the person. The output must be the minimal text span that contains the birth date, month and year as long as they are present. For instance, given a bio like 'I was born on 27th of Decemeber 1990, and graduated high school on 23rd October 2008.' the output should be '27th of December 1990'.
Example: Basinger was born in Athens, Georgia, on December 8, 1953
Example solution: December 8, 1953
Example explanation: The output is correct as it is a valid text span, is of minimal length and is the correct date of birth.

Problem: Nicole Mary Kidman was born on 20 June 1967 in Honolulu, Hawaii, while her Australian parents were temporarily in the United States on student visas

Solution: 20 June 1967