Circa AD 2100 to 2199: The tourists come from the 22nd century, some year after 2140.
Timeline Models
Branching Timelines: Each tour seems to create a new branch, since there are many tours that don’t meet each other. But it’s not explained. Also, there may be many other timelines where Sitra does not seek asylum since Brad asks, “Why now? I’ve led this same tour dozens of times, and you never came before. Why are you suddenly here now?”
Fragile Timeline: Something Sitra’s family did made a vastly altered future.
From the offices of Time Tours, Inc., mid-22nd century ⋙ to an unspecified location, the 1960s. Note: Sitra’s mother escapes to the 1960s with her two children.
From the offices of Time Tours, Inc., mid-22nd century ⋙ to the 107th floor of the South Tower, 11 September 2001. Round trip. Note: Brad’s tour.