In December 2008, at the invitation of Dutoit, Yannick Nézet-Séguin made his first guest-conducting appearance with the orchestra. He returned for a second series of concerts in December 2009. In June 2010, Nézet-Séguin was appointed Music Director Designate, with a scheduled duration under that title from 2010 to 2012, with 2 weeks of scheduled appearances in the 2010–2011 season, and 5 weeks of scheduled appearances in the 2011–2012 season. Eventually, in 2012, he was appointed music director, succeeding Dutoit, who subsequently was named conductor laureate of the orchestra. Nézet-Séguin's initial contract as music director was for 5 seasons, with 7 weeks of scheduled concerts in the 2012–2012 season, 15 weeks in the next 2 seasons, and 16 weeks in the subsequent 2 seasons of his Philadelphia contract. In January 2015, the orchestra announced the extension of Nézet-Séguin's contract to the 2021–22 season. In June 2016, the orchestra announced a further extension of Nézet-Séguin's contract through the 2025–2026 season. In December 2017, the orchestra announced the discontinuation of its relationship with Dutoit and the revocation of his title as its conductor laureate, with immediate effect, in the wake of allegations against him of sexual assault.