Period distributions obtained from model M1 for disk (light grey), diskless (grey), and disk and disless stars (bluish grey) for BDs (left panels) and VLM stars (right panels). The distributions are shown at 1.0 Myr (1st row), 2.1 Myr (2nd row), 3.1 Myr (3rd row), and at 5.1 Myr and 10.1 Myr (4th row). The binsize is 1.0 day. Superimposed on the histograms are observational data – squares for disk objects, crosses for diskless objects, and filled circles for objects not classified as disk or diskless – at 2.1 Myr from RL10 (red symbols) and D14 (blue symbols) for the ONC; at 3.1 Myr using the combined sample of S04 and C10 (blue symbols) for σ Ori; at 5.1 Myr from I08 (blue circles) for NGC 2362; and at 10.1 Myr from S15 (blue symbols) for Upper Sco. Error bars for all observational data were calculated following Burgasser et al. (2003).