As with most of Tuschinski's films, both Matthias Kirste and Alexander Tuschinski receive credit as cinematographer. Most scenes are filmed with two cameras, with each of them operating one camera. In the single-camera sequences, they work as in their previous collaborations: When Tuschinski acts, Kirste operates the camera - and when Tuschinski doesn't appear in the shot, he operates the camera himself.
Konstantin is a film buff. In his apartement, there are numerous film posters and stills decorating the walls. They represent almost all of director Alexander Tuschinski's previous works: Killer Squirrels (2008), Menschenliebe (2010), Mutant Calculator (2011), Hollow Date (2012), Break-Up (2014), The Critic (2015), Gold (2015).
The first scene in Gudrun's apartment was originally filmed to be about three times as long as the edit shown in the final film. During editing, director Alexander Tuschinski decided to cut it "very aggressively", to make the film move much quicker. Originally, the scene included more observations and theoretical discussions about the nature of revolutions, as well as some more visual gags. Several parts of the original, longer edit can be found in Timeless: The Making Of (2016) .
For the sequences set on the Eastern front in 1945, the film uses one of the last drivable Soviet T-34/85 tanks in Germany. The scenes were filmed near Dresden.
Alexander Tuschinski: [original songs] Timeless features four original songs by Alexander Tuschinski, more than any of his films before. Three are interwoven into the narrative to advance the storyline, one is played during the end credits.
Alexander Tuschinski: [squirrels] In the sitcom sequence, the character played by Miles Hunter is wearing a squirrel costume. It is the very same costume that had previously been used by Alexander Tuschinski in Killer Squirrels (2008).