Evolution of the surface rotation period as a function of time when the amount of deuterium in the accreted material (top), the entropy in the accreted material (middle), and the mass accretion history (bottom) are varied. The black crosses show observed rotation periods in very young open clusters. The red, green, and blue diamonds indicate the 25th percentile, the median, and the 90th percentile of each distribution with a sufficient number of stars (see text for details).