Spring Daylight Saving Lose an Hour of Sleep

October 6, 2018

This Sunday marks the 100th anniversary of Daylight Saving Time (DST), and what better way to celebrate than with an hour less sleep in the morning and an extra hour of sunshine at night?

The time change occurs at 2 a.m. local time on Sunday (March 11) – which means clocks everywhere will jump from 1:59 a.m. to 3 a.m. local time.

Spring Daylight Saving Time (not the saving time some people say it is) means that the sun will rise and set one hour later on March 11 than it does on March 10. In effect, the change gives people in the northern hemisphere more sunshine in the evening. And as it turns out, the change may save the lives of koalas (keep reading).

Daylight saving time was the brainchild of Benjamin Franklin, who designed this time change to save energy. But according to timeanddate.com, Franklin’s idea wasn’t implemented in the U.S. until about 100 years ago, on March 31, 1918.

But whether or not DST actually saves energy is up for debate. As Live Science previously reported, the time change slightly reduced energy consumption in the U.S., according to a 2007 study conducted by Oak Ridge National Laboratory senior researcher Stanton Hadley and his colleagues. But a 1998 study found that DST increased residential energy use in Indiana, and temporary changes made in Australia for the 2000 Summer Olympics did not save any energy, according to a 2007 study.

Hadley said, “Whether or not DST saves energy, the main thing is whether the extra hour of sunlight improves people’s lives.” It’s the fact that people want to take advantage of that evening light,” he noted.

But even that may be false.A 2014 study in the Journal of Physical Activity and Health found that people aren’t exercising more as a result of DST. In the study, researchers compared data from people living in Arizona, Colorado, New Mexico, and Utah who participated in the American Time Use Survey from 2003 to 2009. Arizona does not observe the DST, allowing the researchers to compare their results with those of other states. (However, the Navajo Nation, located in northeastern Arizona, abides by the DST).

While DST did not significantly increase activity levels in the study, the researchers noted that the study was limited to the southwestern United States and that it is possible that DST makes a difference in activity levels elsewhere.

There are many other studies on DST. Studies have shown that losing an hour of sleep in the spring is associated with a spike in heart attacks, Live Science has reported. The time change is also associated with more workplace injuries, more cluster headaches and more internet laziness, according to Live Science. a 2017 study in Chronobiology International found that people also tend to miss more medical appointments during their shifts to and from DST.

But there’s that silver lining, too. According to a 2016 study in the journal Biology Letters DST may reduce the number of koalas killed by motorists in Australia. Researchers wrote that this is because wild koalas (Phascolarctos cinereus) are nocturnal, and most wildlife-related vehicle accidents occur at dusk or in the dark, during the evening commute. According to a computer model created by the researchers, shifting daylight hours with DST may reduce the death of these wildlife.

In Australia, where koalas live, Queensland and the Northern Territory (Western Australia) do not follow DST, according to the Australian government.In the U.S., Hawaii is the only state other than Arizona that does not observe daylight saving time.