I am assuming you are asking about Daylight Saving Time (DST), which is the seasonal practice of adjusting clocks forward to maximize evening daylight hours. The Basics of How It Works
Spring Forward: Clocks shift ahead one hour on the second Sunday of March. This moves an hour of daylight from morning to evening.
Fall Back: Clocks return to Standard Time on the first Sunday of November, giving an extra hour of sleep.
The Length: The practice lasts for roughly 34 weeks, covering about 65% of the year. History & Myths Daylight Saving Time
Daylight Saving Time and time zones in the U.S. are defined in the U.S. Code, Title 15, Chapter 6, Subchapter IX – Standard Time .
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