Objective performance measures and subjective sleepiness ratings during the traditional EDWR and intervention RCWR schedules during the day and night. Least-square means (± SE) are estimated from the mixed-effects model under the EDWR (white triangles) and RCWR (black triangles) schedules during the day (top row) and night (bottom row) for attentional failures (A and B) (lapses, reaction time >500 milliseconds), reaction time(C and D), slowest 10% reaction time (E and F), and subjective sleepiness ratings (G and H) plotted across the day. Note that under the day shift interval of 5:00 am to 2:59 pm, Cincinnati started at ∼5:00 am, and all others started at ∼6:00 am. *P < .05, significant differences between conditions at each time point with Tukey-Kramer adjusted post hoc analysis. Shift*CT, interaction between the fixed effects shift and clock time.