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'.

Aniston was born on February 11, 1969, in the Sherman Oaks neighborhood of Los Angeles to Greek-born actor John Aniston and actress Nancy Dow
February 11, 1969

Paul John McGann was born in Liverpool on 14 November 1959, into a Roman Catholic family of Irish origin
14 November 1959

Hart was born on July 6, 1979 in Philadelphia, Pennsylvania
July 6, 1979