Every year, people around the world change their clocks back one hour in the fall and an hour forward in the spring. Yet only a few are aware of the origin behind this practice. Practice of the daylight saving time (DST) has been in effect since the ancient times, however, Benjamin Franklin first conceived the concept of DST in 1784. In his published essay “An Economical Project for Diminishing the Cost of Light”, he proposed the conservation of candles by waking up earlier during the spring time when the days appeared to last longer.

The modern DST is credited to a New Zealand entomologist George Vernon Hudson. After realizing that the days become shorter and lengthen on different times of the year, in 1895, Hudson proposed to the Wellington Philosophical Society that clocks be shifted two hours forward in October and vice versa in March to make use of the extra sunlight. The idea seemed promising, but failed to receive much attention.

In 1905, William Willet, thinking that the extended daylight in the summer days could be utilized, suggested moving the clocks 20 minutes forward each of four Sunday sin April, and switching them back the same way on four Sunday sin September. Willet’s idea of delight saving plan was introduced to the House of Commons in February1908 by Robert Pearce but due to widespread opposition, was not ratified.

During World War II, President Roosevelt established a year round DST called “War Time,” which continued from February of 1942 to September 1945. Before the Uniform Time Act of 1966, train and broadcasting industry in the US independently chose the date of DST causing confusion. The Act stated that DST would begin on the last Sunday of April and end on the last Sunday of October, however, states were free to choose the use of DST.

Since then, DST has experienced several revisions. Now, over seventy countries and billions of people are under its effect each year, but still observe DST on slightly different dates. In the U.S., the current schedule began in 2007 with the Energy Policy act of 2005. With the exception of Hawaii and a portion of Arizona, all U.S. states follow the DST.