When Does "Far Horizons: Orphans of the Helix" (1999) Take Place?
"Orphans of the Helix" is a science fiction prose short story in the anthology "Far Horizons: All New Tales from the Greatest Worlds of Science Fiction" written by Dan Simmons that released May 4th, 1999. So when is "Orphans of the Helix" set?
It takes place in the year:
We know this because the narrator tells us, "Of course the Ousters had experienced the Shared Moment five hundred years ago.", referring to an event near the end of the novel "The Rise of Endymion" (1997), which takes place in 3131 AD. So it must be 3631 AD.

3631 AD
We know this because the narrator tells us, "Of course the Ousters had experienced the Shared Moment five hundred years ago.", referring to an event near the end of the novel "The Rise of Endymion" (1997), which takes place in 3131 AD. So it must be 3631 AD.
3131 + 500 = 3631 AD.