Year 1
From Destiny 1 Wiki
Year 1 was the name given to the first year after the release of Destiny. Year 1 began with the release of Destiny on 9th September, 2014.
Destiny's first expansion, The Dark Below, was released on December 9th, 2014.
Destiny's second expansion, House of Wolves , was released on May 19th, 2015.