Comparison of the mean stellar age of the dynamically cold disks and of the dynamically hot non-disk components of cluster galaxies. Circles and crosses represent galaxies from TNG50 Group 2 and from the Fornax cluster, respectively, color coded by time of infall. The dashed black line represents the one-to-one line. Stars are similarly old in both the cold disk and hot component for ancient infallers, stars become younger in recent infallers, and are about 2 Gyr younger in the cold disk than in the hot component for the most recent infallers.