Time seems scarce. To make the most of it, we expand the boundaries of usable time. We push our work and play into hours traditionally reserved for sleep. We schedule our twenty-four-hour days to take advantage of every minute. Even seconds—divided into unimaginably tiny pieces—seem longer, more usable, more important.

More and more people are awake after midnight or before dawn. Some are working, perhaps keeping the graveyard shift or doing business with foreign markets. Some are playing—increasing numbers of entertainments never close. Some are doing laundry or grocery shopping, just trying to find time to do it all. Neon signs light up the night, announcing a society too busy to sleep.

	Neon sign, about 1994; from a Kinko's business services store, Washington, D.C. Gift of Thomas Zimmerman, with assistance from Kinko's, Inc.

The day never ends. People work at all hours around the clock, often on rotating and irregular shifts. They play at odd times. They shop in the wee small hours. They sleep when they can. The phenomenon is more widespread than ever, driven by economic change and new information technologies. But the human animal is diurnal—we are supposed to sleep when it's dark. People with 'round-the-clock schedules risk chronic fatigue, ill health, and accidents.