Ben Franklin (who took the "early to bed early" phrase to heart) was reportedly the first person to suggest the concept of daylight saving, according to the author of the book Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time, David Prerau.
While performing his role as US ambassador to France, Benjamin wrote that he had been awakened several times at 6 a.m. to realize that the sun was shining earlier than usual. Franklin realized how much oil could be saved overnight if people woke up earlier to do their chores.
It was not until World War I that the time change was carried out on a large scale. Germany was the first state to approve the time change to reduce the hours of artificial lighting and thus save coal that could be used in the war. Soon friends and enemies followed suit.
In the United States, a federal law had standardized the start and end of daylight saving time in 1918, for those States that chose to respect it.
During World War II the United States forced all states to establish Daylight Saving Time as a way to save resources during the war.
During the Arab oil embargo in 1973-74, the United States once again reestablished daylight saving time. Thirty years later, the 2005 energy policy law was promulgated, which requires the extension of summer time from 2007.
Does it really help save energy?
In recent years, several studies have suggested that DST does not really help save energy and might even lead to losses.
The researchers found that daylight saving time did save energy at night, but it was used up during the morning hours of darkness before dawn.
Matthew Kotchen, an economist at the University of California, saw Indiana performing perfectly for the study. With the time change, savings in artificial light were achieved but the consumption of air conditioning increased. This is because even though people arrived at an earlier solar time at their homes, during this time it is still hot, so people turn on the air conditioner upon reaching their homes.
However, other studies have detected energy savings
The time change had saved 1.3 terawatts of electricity in 2011. That figure suggests that during daylight savings time the annual U.S. electricity consumption is reduced. to 0.03 percent and global energy consumption by 0.02 percent.
While these percentages seem small, they could represent significant savings due to the total energy use in the country. Furthermore, the savings in some regions are apparently greater than in others.
California, for example, benefits the most from the schedule, perhaps due to its relatively mild climate that encourages people to stay outdoors later. The report from the Department of Energy states that during daylight saving time, 1% per day was saved in the US.
But Wolff, one of many scholars who have contributed to the federal government report, suggested that the numbers are subject to statistical variability and should not be taken as hard facts.
"Energy gains during daylight saving time in the United States are highly dependent on your location relative to the Mason-Dixon line," Wolff said.
"The North could be a slight winner, because they don't consume as much air conditioning," he said. "But the South is a definite loser in terms of power consumption. The South has more power consumption at night."
Schedule: Healthy or Harmful?
For decades supporters of daylight saving time supported it not only for the energy savings it brings, but also for the healthy lifestyle it provides, Wolff says.
"In a US national study on time use, it was found that during daylight savings time people reduce their time in front of the television and engage in outdoor activities."
But others warn of harmful effects
Till Roenneberg, a chronobiologist at the Ludwig-Maximilians-University of Munich, Germany, said his studies show that our circadian biological clocks, set by light and dark, will never adjust to get an "extra" hour of light at the end of the day. day during summer time.
"The consequence of this is that the majority of the population will drastically decrease productivity, quality of life also decreases, susceptibility to disease increases and one is always tired," said Roenneberg.
One reason why many people in the world develop chronic fatigue is due to “social jet lag”. In other words, your optimal circadian sleep periods are out of sync with your actual sleep schedules. The change in light from morning to night is what increases this delay.
Light does not produce the same effect in the morning as it does in the afternoon. Light in the morning activates the rhythm, but light in the afternoon slows down the rhythm.