Day After Tomorrow is remarkable for its depiction of space exploration "in the colonisation sense, rather than Star Wars and its descendants who show space as a spot to be conquered." She further comments that the themes are "strangely timeless ... the true, unknown part hits you at the very end." Chris Bentley, author of The Complete Gerry Anderson: The Authorised Episode Guide, draws parallels with the Fireball XL5 episode "Faster Than Light", whose plot concerns the problems encountered by the crew of spacecraft traveling at light speed. In a review for Anderson fanzine Andersonic, Vincent Law describes The Day After Tomorrow as an "oddity" and "uncharacteristically lacklustre" by Anderson's standards, stating that while the special "cracks along at a fair old pace", its educational aspects inhibit the story and characterisation. He argues that Jane is the only character who develops over the course of the plot; meanwhile, the adults are "pretty much peripheral" and David is essentially a "miniature Spock". Law also criticises the narration, remarking that Bishop occasionally sounds "like a presenter of one of those old schools programmes from the '70s, just imparting a string of dry facts." He believes the quality of the design and effects to be lower than that of Space: 1999, praising the miniature model work but suggesting that some of the effects are "more in keeping with Blake's 7". He also regards the "info dump" introduction as a weak imitation of the Space: 1999 opening titles and argues that the repeated appearances of the mass–energy equivalence equation, , only confuse the audience. According to Law, the plot about an accident-prone spaceship reflects shifting public attitudes to space exploration during the 1970s, a time "when optimism in the space programme was on the wane". He considers the special to have aged poorly, noting that while Altares is presented as a "lightship" of the future, some of the on-board equipment resembles 20th-century devices such as slide rules and punched cards. John Kenneth Muir praises the "lyrical" script, "stunning" photography and "top-notch" effects. Calling The Day After Tomorrow a "high-tech, science-minded update of the whole Lost in Space format", he comments that its plot mixes action with "psychedelic" moments like the fall into the black hole ("a Kubrickian wonder, a montage dominated by double images, slow-motion photography and the use of a creepy distortion lens. Pretty powerful stuff for a kids' show.") Law regards the