Most of the attentional performance rhythms have been studied in order to organize school peri and extracurricular time in children. The chronopsychological data available on the development of these rhythms are, to our knowledge, rare. It therefore seems necessary, from a developmental and differentia perspective, to address these fluctuations in attentional performance not only in children but also in adults and the elderly. The present study therefore aims to investigate the influence of age and time of day on attentional performance. To do this, 171 participants were divided into three age groups: 88 children (divided into 2 groups: 5-7 years and 9-12 years), 56 adults (divided into 2 groups: 20-35 years and 36-59 years) and 27 seniors (60-72 years). The results indicate that attentional performance varies differently depending on the time of day and that this variation becomes constant and stable with age. Moreover, the level of attention increases with age and this evolution becomes stable from the age of 35.