Within the broad area of time perspective, there are numerous narrower or more specific constructs. One of these, time attitudes, is said to refer to an individual’s emotional and evaluative feelings toward the past, the present, and the future. Scores on the Adolescent Time Inventory–Time Attitudes Scale (ATI-TA) have been shown to be psychometrically sound in a range of cross-sectional studies in different cultural contexts. The present study is the first longitudinal (3 waves) examination of these scores. Participants consisted of 2 samples of adolescents (NS1 = 1,148; NS2 = 464) participating in a study in the United Kingdom. They were 12.5 years old during the first data collection period, with Waves 2 and 3 being 1 and 2 years later, respectively. Results show that at each time point, scores were internally consistent and the hypothesized 6-factor model provided the best fit for the data with factor coefficients in the moderate to strong range. Results also demonstrate configural, scalar, and metric invariance of scores by gender and sample at each time point, and configural invariance across time points. Participants were more positive than negative about the past, present, and future at each time point.