This paper presents a unified solution to the two overarching crises of contemporary cosmology— inflation physics and the nature of dark energy — without introducing hypothetical scalar fieldsor exotic constants, modifying solely elementary relativistic kinematics. We propose a symmetricextension of the Lorentz factor wherein the flow of time asymptotically diverges to infinity both atthe ultra-relativistic limit (v → c) and at the absolute rest limit (v → 0), anchored to the cosmicmicrowave background rest frame. Under this Symmetric Time Approach (STA), the primordialinflationary phase is described as an automatic “temporal inflation” emerging from the initial stateof rest, providing the universe with the necessary span to achieve thermal equilibrium and resolvethe Horizon Problem before the onset of material motion. Analogously, we demonstrate that currentcosmic acceleration emerges as a kinematic optical-temporal illusion: as the universe expands andthe mean macroscopic velocity of matter decays, the corresponding acceleration of the observer’slocal clock distorts astronomical distance measurements, mimicking the signature of a positive cosmological constant. The model is kinematically consistent, preserves classical Special Relativity inhigh-energy regimes, and yields testable quantitative predictions via redshift drift anomalies at highredshifts (z > 3).