The effects of aging and brain damage on time perception are not well understood. In this study, we test the hypothesis that aging affects timing variability and that parietal damage affects timing magnitude. Young and healthy college-age students, older subjects, and a patient with bilateral parietal damage were assessed on their ability to estimate and produce time intervals ranging from four to fifteen seconds. Subjects completed two tasks: production of the duration of a stimulus in seconds and estimation of when the number of seconds presented as a stimulus had elapsed. Data was analyzed via power functions: ψ = Kφβ. Aging and brain damage should theoretically result in either reduced exponents or increased variability in performance. Information processing models separate deficits in perception, decision-making, and memory, allowing more specific analysis of the locus of cognitive deficits. The results of this study show no effects of aging on time perception whereas parietal damage affects temporal processing in significant ways.