TASK DEFINITION: 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'.
PROBLEM: John Charles Carter was born on October 4, 1923, in Wilmette, Illinois, to Lilla (née Baines; 1899–1994) and Russell Whitford Carter (1897–1966), a sawmill operator

SOLUTION: October 4, 1923

PROBLEM: Mortensen was born in Watertown, New York, on October 20, 1958, the son of Grace Gamble (née Atkinson; July 8, 1928 – April 25, 2015) and Viggo Peter Mortensen Sr

SOLUTION: October 20, 1958

PROBLEM: McKellen was born on 25 May 1939 in Burnley, Lancashire, the son of Margery Lois (née Sutcliffe) and Denis Murray McKellen

SOLUTION:
25 May 1939