If you’ve ever heard someone say a meeting is at 1630 and then felt your brain do a small cartwheel, you have met the 24-hour clock. In the United States, we mostly live by the 12-hour clock, with a.m ...

INDIANAPOLIS -- It's known nationwide for rolling back prices. Now Wal-Mart is rolling back something else: its hours. At select locations in markets across the United States, the nation's largest ...

Circadian clocks, the biochemical oscillators that are controlled by the day–night cycle, have a central role in many biological processes. The mechanism underlying the earliest form of such ...