One of the many biological wonders of life on Earth is the near-perfect ways our bodies can sense the passage of time. Known ...

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert.

Daylight saving time started today, March 9, at 2 a.m., which became 3 a.m. just like that. It will end at 2 a.m. Sunday, Nov. 2 when clocks are set back one hour to standard time.

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert.

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert.

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert.

(AP) - The good news: You will get a glorious extra hour of sleep. The bad: It’ll be dark as a pocket by late afternoon for the next few months in the U.S. Daylight saving time ends at 2 a.m. local ...