North Korea has changed time zone to match the South after last week's inter-Korean summit, according to state media.
At 23:30 local time (15:00 GMT) on Friday the country's clocks moved forward 30 minutes to midnight.
The reset is "the first practical step" to speed up Korean unification, the official KCNA news agency said.
Meanwhile, US President Donald Trump says he has a date for his meeting with the North's leader, Kim Jong-Un.
"We now have a date and we have a location, we'll be announcing it soon," Mr Trump told US journalists outside the White House on Friday, adding that he was expecting "very, very good things" to come out of it.
When will Trump and Kim meet?
The meeting was suggested and provisionally agreed in March, after a South Korean delegation met Mr Kim in Pyongyang and later visited the White House.
America's main goal is to secure the North's nuclear disarmament.
Discussions are already believed to be under way to secure the release of three US hostages held in North Korea before the two leaders come face to face.
Trump accepts 'milestone' meeting with Kim
Who are the US hostages in N Korea?
North Korea-Trump talks in 400 words
"We're having very substantive talks with North Korea and a lot of things have already happened with respect to the hostages," said Mr Trump on Friday.
He denied suggestions that he was considering taking US troops out of South Korea as part of the negotiations.
Mr Trump will host South Korea's president Moon Jae-in at the White House on 22 May to discuss the upcoming meeting.
Who else has changed their clock?
In 2007, Venezuela's former leader Hugo Chávez turned the clocks back by half an hour, saying it would allow more people to wake up in daylight.
However, many believed he mostly wanted to distance himself from the time zone of his arch-enemy, the US.
In 2016, his successor, Nicolás Maduro, returned to the previous system, four hours behind GMT, hoping daylight in the evening would reduce energy demands amid a growing economic crisis.
In 2011, Samoa and Tokelau skipped an entire day - and jumped westwards across the international dateline - to align with trade partners.
Are there other unusual time zones?
Canada's Newfoundland province is officially half-an-hour out of step with other Atlantic provinces.
India is half-an-hour ahead of Pakistan and a mere 15 minutes behind Nepal.
Western Australia and South Australia observe a 90-minute time difference across the state boundary.
However, the remote border town of Eucla and the surrounding area, home to a few hundred people, unofficially operate on their own time zone, 45 minutes ahead of Western Australia and 45 minutes behind South Australia.