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 Input: Margot Elise Robbie was born on 2 July 1990 in Dalby, Queensland, to Doug Robbie, a former farm-owner and sugarcane tycoon, and Sarie Kessler, a physiotherapist
Example Output: 2 July 1990

Example Input: Garrett John Hedlund was born on September 3, 1984, in Roseau, Minnesota, to Kristine Anne (née Yanish) and Robert Martin Hedlund
Example Output: September 3, 1984

Example Input: Christopher Hemsworth was born on 11 August 1983 in Melbourne, Victoria, to Leonie (née van Os), an English teacher, and Craig Hemsworth, a social-services counsellor
Example Output:
11 August 1983