Why America Still Changes Clocks for Daylight Saving Time
The daylight hours have been decreasing as the northern hemisphere approaches the darkest time of the year, signaling the end of daylight saving time.
The Clock Change Tradition
Americans, except those in Hawaii and Arizona, will set their clocks back one hour on Sunday, November 2. At 1 a.m., clocks automatically move backward, a tradition known as "falling back," usually done before bedtime on Saturday.
Impact on Sunlight Hours
Since the Summer Solstice, daylight hours have been steadily shortening. By November 2, the sun will set in San Diego as early as 4:56 p.m., according to the National Oceanic and Atmospheric Administration (NOAA).
Sunrise on that day will be at 6:07 a.m., so sun lovers may want to enjoy the daylight as early as possible.
Approaching Winter
Daylight will continue to decline, reaching its lowest point on the Winter Solstice, December 21. On this day, the sun will set as early as 4:47 p.m., marking the shortest day and the longest night of the year.
"The hours of daylight will continue to dwindle, coming to an apex on the day of the Winter Solstice, Dec. 21, at which point the sun will set as early as 4:47 p.m."
Additional Notes
Thanksgiving Day, November 27, will have an early sunset at 4:43 p.m. and heavy carbohydrate meals may contribute to feeling sleepy.
Summary
Daylight saving persists to adjust human activity with seasonal sunlight changes, but declining daylight toward winter signals the ongoing need for these clock shifts.
Author's summary: The biannual clock changes continue due to shifting daylight hours in winter, as the northern hemisphere faces its shortest days and longest nights.