When Does "Red Dead Redemption 2" (2018) Take Place?

"Red Dead Redemption 2" is a western video game written by Dan Houser with Michael Unsworth and Rupert Humphries designed for the PlayStation 4 and XBOX ONE systems and released on October 26th, 2018. 

It takes place on the Red Dead timeline in the year: 

1899 AD 

We know this because readable tombstones in the game's graveyards during the narrative's main action include death dates up to "May 23 1897" and characters mention the impending turn of the century in 1900 AD as something coming but not yet happening. 

Furthermore, Uncle says, "Why we having a war with the goddamn Philippines? Who cares about the Philippines? What even are the Philippines?" and the Philippine–American War lasted from February 4th, 1899 AD to July 4th, 1902 AD. In the opening scene, Hosea Matthews exclaims, "This weather! It's May!" So it's May of 1899 AD at the beginning of the story. 

This Reddit user measured the amount of time that passes over the game, without the epilogue. It was clocked at 4 months and 1 week, so the main action takes place entirely within the calendar year of 1899 AD. 

This video examines its exact setting. 

Additionally, there is an epilogue that starts with only a title card reading, "Some years later..." but is eventually identified by a "The Blackwater Ledger" newspaper headline that reads, "President Signs 1907 Immigration Act". This is a real-world bill, signed into law on February 20th, 1907 AD. 

There's a title card reading "A few months later..." about one-fifth through the epilogue as well and another newspaper includes the headline "BUREAU OF INVESTIGATION FOUNDED" announcing the creation of the real-world Bureau of Investigation, which occurred on July 26th, 1908 AD (it was renamed in 1932 AD). So the epilogue continues into July of 1908 AD. 

This video examines the epilogue's exact setting.