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'.

[EX Q]: Benjamin Géza Affleck-Boldt was born on August 15, 1972, in Berkeley, California
[EX A]: August 15, 1972

[EX Q]: Welch was born as Jo Raquel Tejada on September 5, 1940 in Chicago, Illinois
[EX A]: September 5, 1940

[EX Q]: Gainsbourg was born on 21 July 1971 in London, to English actress and singer Jane Birkin and French actor and singer-songwriter Serge Gainsbourg
[EX A]:
21 July 1971