An early pitch for the story that became "Future Tense" had the USS Defiant (from The Tholian Web (1968)) appearing instead of a timeship from the 31st century. The Defiant later appeared in In a Mirror, Darkly (2005) and In a Mirror, Darkly, Part II (2005).
Among the images in "Daniels' database" is a news article on President George W. Bush's State of the Union Address for 2003.
This episode marks the first appearance of the Tholians since their introduction in The Tholian Web (1968) 35 years earlier.
Behind the captain, while Reed is cutting into the timeship, on a shelf sits the exocomp prop device from The Quality of Life (1992) that was also used in Dead Stop (2002) to repair Reed's leg.
Among the images in "Daniels' database" are schematics for a Klingon Raptor-class ship, an Intrepid-class starship (possibly USS Voyager), an Intrepid-class aeroshuttle, the Mir space station, the US space shuttle, a Nygean ship, a 24th century Romulan D'deridex-class warbird, a Nova-class ship from the same era, the unnamed ship that attacked Enterprise in Fight or Flight (2001), and an upside-down Suurok-class starship.