Upper panel: distribution of the relative difference between the estimated and true age of the old stellar population. The sample is split as a function of the true age: t_f = 1 Gyr, t_f = 2 Gyr, t_f = 3 Gyr, and t_f = 4,   5 Gyr. Lower panel: distribution of the ratio of the estimated and true age of the young stellar population in logarithmic units. The sample is split as a function of the true age: t_ySP = 0.01 Gyr, t_ySP = 0.03 Gyr, t_ySP = 0.1 Gyr, and t_ySP = 0.3 Gyr.