European lawmakers vote to end daylight saving time in 2021: Report

European lawmakers have voted to stop observing daylight saving time beginning in 2021, according to Reuters.

European Parliament voted 410 to 192 in favor of operating on a single time on Tuesday. A parliament report in favor of ending the practice of adjusting clocks twice a year stated that studies link the practice to cardiovascular disease and weakened immune systems because they interrupt biological clocks, Reuters reported.

European Union law requires all countries within the bloc to participate the seasonal time shift. The decision is not final, but rather the beginning of discussions about the issue, on which individual countries have yet to take a stance.

Daylight saving time was invented to make the best use of daylight hours and has been used throughout much of the U.S., Canada and Europe since World War I. In Europe, where it is referred to as "summer time," it begins on the last Sunday of March and ends on the last Sunday of October.

Countries in the European Union would not be able to change their clocks twice a year, but they would be free to decide which time zone they want to be in.

In the U.S., Hawaii and Arizona do not observe daylight saving time, and other states are considering making the switch as well.

Most countries outside North America and Europe do not observe daylight saving time.

In 2011, Russia switched to permanent summer time but later shifted to permanent winter time in 2014 after public complaints, according to Reuters.

ABC News' Fergal Gallagher and Ben Gittleson contributed to this report.