Objectives <p>Mindfulness meditation has been reported to lengthen perceived durations, but it remains unclear whether these effects reflect meditation itself or confounding factors such as task repetition. Brief, app-based mindfulness practices are widely used by novices, yet they may induce states of relaxation rather than genuine mindfulness. The present study investigated whether short meditation sessions produce unique effects on duration judgments, or whether repetition better accounts for observed changes.</p> Methods <p>In Experiment 1A, 178 adults completed an online visual temporal bisection task before and after a brief 5-min interval which involved either a focused attention meditation (<i>n</i> = 63), unfocused attention meditation (<i>n</i> = 64), or doing nothing (<i>n</i> = 50). Experiment 1B (<i>n</i> = 60) was a laboratory replication of Experiment 1A. In Experiment 2 (<i>n</i> = 64), the order of sessions was reversed: participants first completed a 5-min meditation and then performed the bisection task twice, allowing direct assessment of repetition effects.</p> Results <p>In both Experiments 1A and 1B, stimulus durations were overestimated after the interval across all groups, with only small and inconsistent group differences. In Experiment 2, a clear leftward shift in the psychophysical function occurred from the first to the second task session, indicating robust overestimation driven by task repetition.</p> Conclusions <p>The findings suggest that brief meditation sessions do not uniquely affect time perception in participants with no prior meditation experience. Instead, task repetition emerged as the dominant driver of overestimation, consistent with attention-based models of duration judgments. These results highlight the need to distinguish meditation-specific influences from the more general effects of relaxation and repeated task exposure.</p> Preregistration <p>This study was not preregistered.</p>