Time for clocks to spring forward, as daylight saving time begins at 2 a.m. Sunday.

Some will be glad for the extra hour of daylight, while others will bemoan the loss of an hour of sleep—or arrive at church an hour late after forgetting the change.

The modern version of Daylight Saving Time was first implemented by Germany and Austria-Hungary, starting on April 30, 1916.

In the United States, the measure wasn’t adopted until the Standard Time Act of March 19, 1918.

But many countries have either abolished the practice of daylight saving time, or never instituted such a practice to begin with.

Closer to home, Arizona and Hawaii are the only U.S. states to not observe daylight saving time, though overseas territories Puerto Rico, American Samoa, Guam, the Northern Mariana Islands and the U.S. Virgin Islands don’t, either.

Adding daylight to evenings benefits businesses and activities that exploit sunlight after working hours, such as sports. However, other causes can be negatively affected.

Although an early goal of daylight saving time was to reduce evening use of incandescent lighting, modern systems of lighting and heating and cooling differ greatly, and research about the effect of DST is limited or contradictory.

And that’s not to mention the problems that can be caused by forgetting to change those clocks.

If you do forget, just wait until 2 a.m. on Nov. 2, the end of daylight saving time, and you’re clock will be correct once again.