Set in a version of 2015 that feels strikingly suburban yet technologically saturated, The 6th Day depicts an Earth where human cloning is legally prohibited under "Sixth Day" laws but biological engineering is a ubiquitous consumer reality. The world is defined by commercialized biotechnology, where storefronts like "RePet" offer instant replacements for deceased family pets, and medical science has mastered the rapid synthesis of human organs for transplants. Despite these advancements, the physical environment remains recognizable, with 20th-century urban layouts retrofitted with sleek, neon-lit digital infrastructure.

Societal dynamics are governed by the tension between religious/ethical traditionalism and the overreach of monopolistic corporations. Replacement Technologies, the film's central antagonist entity, operates as a shadow power capable of subverting the law through illegal human replication. The Earth in this timeline is a post-privacy society where biometric markers—such as thumbprints and DNA—are the primary currency for security and commerce. The film suggests a divergence from our reality triggered by accelerated breakthroughs in the late 1990s (post-Dolly the Sheep), leading to a world where biological data is the ultimate corporate asset.

The film’s 2015 includes several successful predictions, most notably the integration of biometric scanners in everyday life and the concept of smart appliances; the film features a refrigerator that monitors milk levels and orders replacements, a direct precursor to modern IoT and smart home ecosystems. While the "Whispercraft" (hybrid helicopter-jets) and instantaneous full-body cloning remain science fiction, the film accurately anticipated the rise of self-driving vehicle prototypes and the ethical debates surrounding synthetic life and gene editing. However, the film's depiction of holographic virtual assistants and laser-based consumer goods (like razors) has transitioned into the real world primarily as niche or augmented reality applications rather than the physical staples shown on screen.