We're all familiar with "spring ahead" and "fall back" in reference to daylight savings time...with the latter giving us an extra hour of sleep tonight.
Wikipedia reports that the modern idea of daylight savings was first proposed in 1895, and first implemented by Germany and Austria-Hungary in 1916.
Many countries have used it at various times since then, with much of the US starting it in the 1950s and 60s, and expanding it after the 1970s energy crisis.
Adding daylight to evenings benefits retailing, sports, and other activities that exploit sunlight after working hours...but it can cause problems for evening entertainment and other work tied to the sun or sunset, such as farming or fireworks.
Although an early goal was to reduce evening use of lighting...its effect on modern-day energy use is unclear. Its effects on health are clearer, with male suicide rates rising after 'springing ahead' an hour, and heart attacks more common then - but less common in the 'fall back.'
And, anyone with more than a handful of clocks knows that daylight savings...complicates timekeeping.