Question: Callum Smith, is a British professional boxer, who competes in the super-middleweight division, and held the European, the British, and the WBC Silver titles between 2015 and 2017, he's the youngest of the Smith brothers, Stephen Francis Smith, is a British professional boxer, born on which date?

Context articles: Ohara Davies
George Groves (boxer)
Luke Campbell (boxer)
James DeGale
Muhammad Waseem
Stephen Smith (boxer)
Liam Smith (boxer)
Paul Smith (boxer)
Callum Smith
Tommy Coyle (boxer)

Ohara Davies (born 9 February 1992) is a British professional boxer.
 He is a light welterweight who is trained by Tony Sims.
 He is the former WBC silver champion.
 He was also the former English super lightweight champion.
 As of April 2017, he was ranked in the top 10 in the world at light welterweight by both the WBC and IBF.
George Groves (born 26 March 1988) is a British professional boxer.
 He has held the WBA (Super) super-middleweight title since May 2017, and previously the European, British, and Commonwealth super-middleweight titles between 2010 and 2014.
 As an amateur, Groves won the ABA middleweight title twice, in 2007 and 2008.
Luke Campbell, {'1': ", '2': ", '3': ", '4': "} (born 27 September 1987) is a British professional boxer.
 He held the WBC Silver and Commonwealth lightweight titles from 2016 to 2017, and has challenged once for the WBA and "Ring" magazine lightweight titles in 2017.
 As an amateur, Campbell won gold medals at the 2008 European Championships and 2012 Olympics, as well as silver at the 2011 World Championships, all in the bantamweight division.
James Frederick DeGale, {'1': ", '2': ", '3': ", '4': "} (born 3 February 1986) is a British professional boxer.
 He has held the IBF super-middleweight title since 2015, having previously held the British super-middleweight title from 2010 to 2011, and the European super-middleweight title from 2011 to 2012.
 As of May 2017, he is ranked as the world's best super-middleweight by "The Ring" magazine and the Transnational Boxing Rankings Board, and third by BoxRec.
 As an amateur, DeGale represented Great Britain at the 2008 Olympics, winning a gold medal in the middleweight division.
 By later becoming IBF champion, he became the first British boxer ever to have won both an Olympic gold medal and a professional world title.
Muhammad Waseem (born 29 August 1987) is a Pakistani professional boxer from Quetta, Balochistan, Pakistan, who competes at the flyweight division of the WBC, and is Pakistan's first professional boxer to have ever held a WBC title.
 He is the Current WBC Silver Flyweight Champion.
Stephen Francis Smith (born 22 July 1984 is a British professional boxer.
 He is the current WBC Silver super featherweight champion and a former British featherweight and British super featherweight champion, he is also a former Commonwealth featherweight champion.
Liam Smith (born 27 July 1988) is a British professional boxer.
 He held the WBO light-middleweight title from 2015 to 2016, having previously held the Commonwealth light-middleweight title from 2012 to 2013, and the British light-middleweight title from 2013 to 2015.
 Liam is the younger brother of Paul Smith and Stephen Smith, and the older brother of Callum Smith; all of whom are also professional boxers.
Paul Smith Jr. (born 6 October 1982) is a British professional boxer.
 He held the English middleweight title in 2008; the British super-middleweight title twice between 2009 and 2014; and has challenged three times for a super-middleweight world title.
Callum Smith (born 23 April 1990) is a British professional boxer who competes in the super-middleweight division, and held the European, the British, and the WBC Silver titles between 2015 and 2017.
 He is the youngest of the Smith brothers—Paul, Stephen, and Liam—all of whom are professional boxers.
Tommy Coyle (born 2 September 1989) is a British professional boxer.
 He has challenged for the Commonwealth lightweight and British super-lightweight titles, and is a former WBC Silver International lightweight champion.
 He is the older brother of Leeds United footballer Lewie Coyle.