When Does the Film "Thor: Ragnarok" (2017) Take Place?
"Thor: Ragnarok" is a comedy science fiction superhero film written by Eric Pearson with Craig Kyle, Christopher Yost, and Stephany Folsom [adapting "Thor" #277-#278 v1 (1978) by Roy Thomas as well as "The Incredible Hulk" #93-#95 v3 (2006) and "The Incredible Hulk" #101 v3 (2006), all by Greg Pak] that released October 24th, 2017. So when is "Ragnarok" set?
It takes place on the Marvel Cinematic Universe timeline in the year:
We know this because Thor Odinson says, "Sokovia, Ultron; that was 2 years ago." clearly referencing the events of "The Avengers: Age of Ultron" (2015), which take place in either June, July, or August of 2015 AD.

2017 AD
We know this because Thor Odinson says, "Sokovia, Ultron; that was 2 years ago." clearly referencing the events of "The Avengers: Age of Ultron" (2015), which take place in either June, July, or August of 2015 AD.
2,015 + 2 = 2,017.
Additionally, there is an end-credits scene which takes place mere moments to hours before the opening events of "The Avengers: Infinity War" (2018), which definitively take place in 2018 AD.
This Geekritique article and video examines its exact setting.
It is a chronologically midway film in the Marvel Cinematic Universe.
v

