This weekend, skywatchers in 13 states will experience a celestial rarity—a "black moon." The phenomenon, occurring on Saturday, November 30, will happen only in Western time zones of the United ...

The twice annual change isn't observed everywhere in the U.S. According to the Department of Transportation, which oversees the nation's time zones, there are two states and five U.S. territories ...

The invention of railroads ushered in a new era of land travel, and forever changed the way humans perceive time.

Since passage of the Energy Policy Act of 2005, daylight saving time in the United States has begun annually on the second Sunday in March and ended on the first Sunday in November. When daylight ...

Some of those states made the provision contingent on neighboring states doing the same thing. Idaho, which is split into two different time zones, passed a measure that would make the switch to ...

Agricultural groups led a 1919 fight to repeal DST. All time zones in the United States that observe DST were changed by the Energy Policy Act of 2005. The act meant that in 2007, DST would now ...