Question: In what month was the Rihanna song that Mikky Ekko is best known for being featured on released?

Context paragraphs:
Mikky Ekko: Mikky Ekko (born John Stephen Sudduth; December 17, 1984) is an American recording artist and record producer from Louisiana, signed to RCA Records.  He is best known for being featured on Rihanna's 2013 single "Stay", which has charted in multiple countries worldwide, becoming Ekko's first-charting material.  Ekko released his debut studio album, "Time" in January 2015 through RCA Records.

Dimitri Tikovoï: Dimitri Tikovoï is a French record producer and DJ who has worked with bands including Placebo, The Horrors, Charli XCX, Mikky Ekko, Marianne Faithfull, and Nicola Roberts.  In 2002, Tikovoi released an album under the name "Trash Palace" ("Positions", featuring Brian Molko, John Cale, Marc Almond, Asia Argento and others).

We Remain: "We Remain" is a song by American singer Christina Aguilera, taken from "", the soundtrack to the 2013 American science-fiction adventure film "".  It was released as the third single from the soundtrack on October 1, 2013, following Coldplay's "Atlas" and Sia's "Elastic Heart".  Composed by Ryan Tedder, Brent Kutzle and Mikky Ekko, "We Remain" is an arena pop power ballad about perseverance.  Contemporary music critics lauded the song for its sound and picked it as one of the highlights from the soundtrack.  The single appeared on a few national record charts including Belgium and South Korea.

Stay (Rihanna song): "Stay" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  It features guest vocals by Mikky Ekko, and was released as the second single from the album on January 7, 2013.  "Stay" was co-written by Ekko and Justin Parker.  The song's lyrical content speaks of temptation and the inability to resist true love.  Music critics were generally positive in their opinion regarding the balladry, with most describing it as a standout track on the album, though a few labeled it as boring.  The song was featured on the third-season finale of the TV Show Younger.

32 Levels: 32 Levels is the debut studio album by American record producer Clams Casino.  It was released on July 15, 2016, by Columbia Records.  The album contains guest appearances from Lil B, A$AP Rocky, Vince Staples, Sam Dew, Mikky Ekko, Kelela, and Samuel T. Herring, among others.

Rapor: Rapor is an EP from Active Child released on October 22, 2013.  The first single for the EP was "Evening Ceremony", which was featured in the movie The Host.  The second single, "She Cut Me" was released on August 12, 2013.  The third single, "Subtle" featuring Mikky Ekko, was released on September 10, 2013.

Kingdom (Gorgon City album): Kingdom is the upcoming second studio album by English electronic music production duo Gorgon City.  It is scheduled to be released in 2017, through Virgin EMI Records.  The album is set to feature the likes of Vaults, Tink, Mikky Ekko, Wyclef Jean and Elderbrook.

Déjà Vu (Giorgio Moroder album): Déjà Vu is the fourteenth studio album by Italian DJ Giorgio Moroder, his first album, after a 23-years hiatus, since "Forever Dancing" (1992).  It was released on 12 June 2015, and features collaborations with: Britney Spears, Kylie Minogue, Kelis, Sia, Charli XCX, Mikky Ekko, Foxes and Matthew Koma, among others.  On 20 January 2015, the collaboration with Kylie Minogue, "Right Here, Right Now", was officially released, along with a video teaser.

Summertime '06: Summertime '06 is the debut studio double album by American rapper Vince Staples.  It was released on June 30, 2015, by ARTium Recordings, Blacksmith Records and Def Jam Recordings.  The album was primarily produced by No I.D., alongside a variety of high-profile record producers, including DJ Dahi, Clams Casino, Brian Kidd, Christian Rich and Mikky Ekko.  The album was supported by three singles: "Señorita", "Get Paid" and "Norf Norf".

Time (Mikky Ekko album): Time is the debut studio album by American recording artist Mikky Ekko.  The album was released worldwide on January 16, 2015 by RCA Records, except for the United States where it was released on January 20.

Supporting paragraphs: Mikky Ekko Stay (Rihanna song)
Answer: January