The Metal Gear Solid games span across decades, though not in chronological order. This should clear the timeline up.
The last major release in the series was Metal Gear Solid V: The Phantom Pain which was released ... and rereleased for the ...
Snake returns to the battlefield in Metal Gear Solid 5: The Phantom Pain as Big Boss, in the midst of a sandstorm riding a white horse. It is 1984, nine years after the fighting, the destruction ...