Considering that the recent history of E-S0 galaxies can be approximated by Pure Luminosity Evolution (PLE), we have examined a set of PLE models in order to delimit the epoch in which the majority of the red galaxy population moved away from this simple evolution framework. The models assume that they were assembled and formed most of their stars at a given formation redshift (z f), and that they have evolved without merging or substantial dust obscuration since then. Comparing the model predictions with real data, we conclude that most of E-S0’s at low and intermediate luminosities must have been progressively built up at 1 < z < 2, being the bulk of formation at z ˜ 1. 5, as recently claimed by several observational studies.