["Journal of Behavioral Decision Making, Volume 39, Issue 3, July 2026. ", "\nABSTRACT\nThe date‐delay effect, a well‐established anomaly in intertemporal choice, describes the tendency for individuals to prefer future rewards more when they are described using calendar dates (e.g., “July 1, 2026”) compared to delays (e.g., “100 days later”). Although prior research has primarily attributed this effect to reduced perceived temporal distance under the date frame, evidence for this mechanism comes almost exclusively from short delay distance. Through five experiments systematically manipulating delay distance (15, 105, and 450 days) and description frame, the present study suggests that the date‐delay effect is robust across both short and long delays. Critically, however, the underlying cognitive mechanism shifts with delay distance. Under short delays (15 days), the effect is mediated by reduced perceived temporal distance, supporting the Temporal Distance Perception Hypothesis. Under long delays (450 days), where frame‐induced differences in perceived temporal distance disappear, the effect is instead driven by increased perceived temporal ambiguity, validating the Temporal Ambiguity Perception Hypothesis. Study 5 further validated the robustness of the findings from Studies 3 and 4, demonstrating that the two mechanisms operate respectively across different delay distances. These findings support a context‐dependent dual‐process account aligned with the attribute‐comparison model, revealing that the date‐delay effect may be underpinned by distinct temporal perception mechanisms operating at different temporal distances. This refined theoretical framework advances our understanding of how temporal framing shapes intertemporal decisions.\n"]