When Does "Metal Gear Solid V: The Phantom Pain" (2015) Take Place?
"Metal Gear Solid V: The Phantom Pain" is a spy video game written by Hideo Kojima with Shuyo Murata, Hidenari Inamura, and Etsu Tamari designed for the PlayStation 3 and PlayStation 4 systems, that released September 1st, 2015. So when is "The Phantom Pain" set?
It takes place on the fictional Metal Gear timeline in the year:
We know this because very early in the first level of the game, a character clearly states 9 years have passed since the events of the previous game, "Metal Gear Solid V: Ground Zeroes" (2014), which takes place in March of 1975 AD.

1984 AD
We know this because very early in the first level of the game, a character clearly states 9 years have passed since the events of the previous game, "Metal Gear Solid V: Ground Zeroes" (2014), which takes place in March of 1975 AD.
1975 + 9 = 1984.