President Trump signaled his support for daylight saving time on Twitter. (Jabin Botsford/The Washington Post)

President Trump on Monday offered his endorsement to a growing movement to adopt daylight saving time year-round, which would end the century-old practice of semiannual clock adjustments in the United States.

“Making Daylight Saving Time permanent is O.K. with me!” Trump said on Twitter.

His tweet followed the introduction of a bill last week by Sen. Marco Rubio (R-Fla.) that would make daylight saving time a year-round reality. Rep. Vern Buchanan, another Florida Republican, introduced matching legislation of the Sunshine Protection Act in the House.

Rubio went on Twitter shortly after Trump tweeted, writing: “Hopefully we can pass it in Congress & get it to your desk soon.”

Several state-level initiatives have also been launched, including in Florida, where last year lawmakers signaled their intent to go year-round with daylight saving time and where Trump has his Mar-a-Lago resort.

On Saturday, a similar bill passed in the Washington state House and is awaiting action in its Senate.

Under federal law, states are only empowered to opt out of daylight saving time and remain on standard time year round.

Daylight saving time was implemented haphazardly for decades, until Congress passed the Uniform Time Act in 1966 to bring some order to the system.

Congress has extended the duration of DST twice, and it now covers two-thirds of the year. Since 2007, DST has begun on the second Sunday in March and ended on the first Sunday in November.