North Korea has announced it will move its clocks back 30 minutes to create a new "Pyongyang time", breaking from a standard imposed by "wicked" Japanese imperialists more than a century ago.
The change will put the standard time in North Korea at GMT+8:30, 30 minutes behind South Korea which, like Japan, is at GMT+9:00.
North Korea said the time change, approved by its rubber-stamp parliament, would come into effect from August 15 which this year marks the 70th anniversary of the Korean peninsula's liberation from Japan's 1910-45 colonial rule.
"The wicked Japanese imperialists committed such unpardonable crimes as depriving Korea of even its standard time while mercilessly trampling down its land," the North's official KCNA news agency said.
Standard time in pre-colonial Korea had run at GMT+8:30 but was changed to Japan standard time in 1912.
KCNA said the parliamentary decree reflected "the unshakeable faith and will of the service personnel and people on the 70th anniversary of Korea's liberation."
Seoul's unification ministry, which deals with cross-border affairs, said a different time zone between North and South posed a number of possible challenges, including for operations at the jointly-run Kaesong industrial complex that lies just inside North Korea.
"In the short term, there might be some inconvenience in entering and leaving Kaesong," ministry spokesman Jeong Joon-Hee said.
"And in the longer term there may be some fallout for efforts to unify standards and reduce differences between the two sides."