Spring forward, fall back. Sound familiar? The catchphrase describes the practice of daylight saving time (DST), or moving the clock forward by one hour in summer to make evening daylight last longer. The practice is common in North America and Europe, with people changing their clocks at the start of spring and then reverting them back in the middle of fall.

While some may have heard that Benjamin Franklin, an 18th-century founding father of the United States, invented DST, credit actually goes to New Zealand entomologist George Hudson. He valued after-work hours of sun to collect insects, which led him in 1895 to propose shifting clocks two hours forward in summer and two hours back in winter. His idea was not very popular.

Hudson's idea took some time to catch on — and when it did, it was in a totally different part of the world. In 1916, the German and Austrian Empires ordered that all clocks be moved forward by one hour on April 30 in order to try to save fuel for the war effort by minimizing the need for artificial lighting. The UK, France and the US soon followed, but countries dropped the shift after WWI ended.

DST was reinstituted in much of Europe during WWII, including in Germany under Adolf Hitler. National practices varied greatly through the 1970s energy crisis. In 1980, the EU's forerunner began to coordinate divergent clock changes. Since 2001, EU states have been obliged to switch to summer time on the last Sunday in March and back to standard time, or winter time, on the last Sunday in October.

In 2018, European Commission President Jean-Claude Juncker pledged to do away with the bloc's seasonal time changes in 2019. Member states could choose to keep summer or winter time. His cited an online EU survey in which 84 percent of respondents voted to end clock changes. However, only 4.6 million people voted in the poll and nearly three-quarters of all votes were from Germany.