The current study seeks to extend the currently available treatments for SWSD by addressing the putative root cause of the problem—the inability of night-shift workers with or without SWSD— to obtain adequate daytime sleep in the face of the circadian drive for alertness that increases across the biological day. Even healthy, young subjects who are sleep-deprived overnight exhibit daytime sleep marked by frequent awakenings and low sleep efficiency, less slow-wave sleep, and altered sleep architecture, e.g. earlier predominance of REM sleep. Many night-workers routinely report 3-6 hours of habitual sleep duration for daytime sleep. Pharmacological interventions to decrease awakenings and improve total sleep time during daytime sleep could improve subsequent alertness during a night shift. Improving the wakefulness of night-shift workers over the nighttime could result in substantial benefits for the individual workers, improve workplace productivity and safety, and improve public health.