Passage: The album's lead single "Hold It Against Me" debuted at number-one on the Billboard Hot 100, becoming Spears's fourth number-one single on the chart and making her the second artist in history to have two consecutive singles debut at number one, after Mariah Carey. The second single "Till the World Ends" peaked at number three on the Billboard Hot 100 in May, while the third single "I Wanna Go" reached number seven in August. Femme Fatale became Spears's first album in which three of its songs reached the top ten of the chart. The fourth and final single "Criminal" was released in September 2011. The music video caused controversy when British politicians criticized Spears for using replica guns while filming the video in an area of London that had been badly affected by the 2011 England riots. Spears's management briefly responded, stating, "The video is a fantasy story featuring Britney's boyfriend, Jason Trawick, which literally plays out the lyrics of a song written three years before the riots ever happened." In April 2011, Spears appeared in a remix of Rihanna's song "S&M". It reached number one in the US later in the month, giving Spears her fifth number one on the chart. On Billboard's 2011 Year-End list, Spears was ranked number fourteen on the Artists of the Year, thirty-two on Billboard 200 artists and ten on Billboard Hot 100 artists. Spears co-wrote "Whiplash", a song from American pop rock band Selena Gomez & the Scene' third album When the Sun Goes Down.In June 2011, Spears embarked on the Femme Fatale Tour. The first ten dates of the tour grossed $6.2 million, landing the fifty-fifth spot on Pollstar's Top 100 North American Tours list for the half-way point of the year. The tour ended on December 10, 2011 in Puerto Rico after 79 performances. A DVD of the tour was released in November 2011. In August 2011, Spears received the Michael Jackson Video Vanguard Award at the 2011 MTV Video Music Awards. The next month, she released her second remix album, B in the Mix: The Remixes Vol. 2. In...

Question: when did Spears end her engagement?
January 2013