Question: The 2015–16 Xavier Musketeers women's basketball team represented Xavier University during the 2015–16 NCAA Division I women's basketball season, they were third year members of the newly reorganized Big East Conference, a collegiate athletic conference that competes in NCAA Division I in all sports except football, and has been officially recognized as a Division I multi-sport conference, effective on which date?
Context: The 2015–16 Xavier Musketeers women's basketball team represented Xavier University during the 2015–16 NCAA Division I women's basketball season.  The Musketeers, led by fifth-year head coach Brian Neal, they played their games at the Cintas Center and were third year members of the newly reorganized Big East Conference.  They finished the season 17–13, 8–10 in Big East play to finish in a tie for seventh place.  They lost in the first round of the Big East Women's Tournament to Butler. The 2014–15 Xavier Musketeers women's basketball team represented Xavier University during the 2014–15 NCAA Division I women's basketball season.  The Musketeers, led by fourth-year head coach Brian Neal, they played their games at the Cintas Center and were second year members of the newly reorganized Big East Conference.  They finished the season 18–15, 8–10 to finish in seventh place.  They advanced to the quarterfinals of the Big East Women's Tournament where they to DePaul.  They were invited to the Women's Basketball Invitational where they defeated to William & Mary in the first before losing to Siena in the quarterfinals. The 2016–17 Xavier Musketeers men's basketball team represented Xavier University during the 2016–17 NCAA Division I men's basketball season.  Led by eighth-year head coach Chris Mack, they played their games at the Cintas Center in Cincinnati, Ohio and were fourth-year members of the Big East Conference.  They finished the season 24–14, 9–9 in Big East play to finish in seventh place.  In the Big East Tournament, they defeated DePaul and Butler before losing to Creighton in the semifinals.  They received an at-large bid to the NCAA Tournament as a No. 11 seed in the West region where they defeated Maryland, Florida State, and Arizona before losing in the Elite Eight to Gonzaga. The 2014–15 Xavier Musketeers men's basketball team represented Xavier University during the 2014–15 NCAA Division I men's basketball season.  Led by fifth year head coach Chris Mack, they played their games at the Cintas Center and were second year members of the Big East Conference.  They finished the season 23–14, 9–9 in Big East play to finish in sixth place.  They advanced to the championship game of the Big East Tournament where they lost to Villanova.  They received an at-large bid to the NCAA Tournament where they defeated Ole Miss in the Second Round and Georgia State in the Third Round before losing in the Sweet Sixteen to Arizona. The 2013–14 Xavier Musketeers men's basketball team represented Xavier University during the 2013–14 NCAA Division I men's basketball season.  Led by fifth year head coach Chris Mack, they played their games at the Cintas Center and were first year members of the newly reorganized Big East Conference.  They finished the season 21–13, 10–8 in Big East play to finish in a three way tie for third place.  They advanced to the semifinals of the Big East Tournament where they lost to Creighton.  They received an at-large bid to the NCAA Tournament where the lost in the First Round ("First Four") to NC State. The Big East Conference (stylized as BIG EAST) is a collegiate athletic conference that competes in NCAA Division I in all sports except football, which is not sponsored.  The conference has been officially recognized as a Division I multi-sport conference, effective on August 1, 2013. The 2011–12 Xavier Musketeers men's basketball team represented Xavier University in the 2011–12 NCAA Divisions I Men's Basketball Season.  Xavier was led by head coach Chris Mack in his third season at Xavier.  The Musketeers competed in the Atlantic 10 Conference and played their home games at the Cintas Center.  Xavier finished the season 28–3,10–6 in A-10 play to finish in tie for third place in conference.  The Musketeers lost to St. Bonaventure in the championship of the A-10 Tournament.  Xavier received a #10 seed in the NCAA Tournament.  The Musketeers defeated Notre Dame and Lehigh to reach the Sweet Sixteen where they were defeated by Baylor. The 2016–17 Xavier Musketeers women's basketball team represented Xavier University during the 2016–17 NCAA Division I women's basketball season.  The Musketeers, led by sixth-year head coach Brian Neal, they played their games at the Cintas Center and were fourth year members of the newly reorganized Big East Conference.  They finished the season 12–18, 4–14 in Big East play to finish in a tie for seventh place.  They lost in the first round of the Big East Women's Tournament to Butler. The 2015–16 Xavier Musketeers men's basketball team represented Xavier University during the 2015–16 NCAA Division I men's basketball season.  Led by seventh year head coach Chris Mack, they played their games at the Cintas Center and were third year members of the Big East Conference.  They finished the season 28–6, 14–4 in Big East play to finish in second place.  They defeated Marquette in the quarterfinals of the Big East Tournament to advance to the semifinals where they lost to Seton Hall.  They received an at-large bid to the NCAA Tournament where they received a #2 seed.  They defeated Weber State in the First Round to advance to the Second Round where they lost to Wisconsin. The 2008–09 Xavier Musketeers men's basketball team represented Xavier University in the 2008–09 college basketball season.  They were led by head coach Sean Miller in his fifth and final season at Xavier.  The Musketeers were members of the Atlantic 10 Conference and played their home games at the Cintas Center.  Xavier finished the season with a record of 27–8, 12–4 in A-10 play to win the regular season championship.  The Musketeers lost in the quarterfinals of the A-10 Tournament to Saint Louis.  They received an at-large bid to the NCAA Tournament as a #4 seed.  The Musketeers defeated Portland State and Wisconsin to advance to the Sweet Sixteen before losing to Pittsburgh.
Answer: August 1, 2013