All in all, this is one of Kim Jong Un's less crazy moves.
Currently North Korea shares its time zone with South Korea and Japan (nine hours ahead of us), which was set during Japan's rule over a united Korea in the early 20th century, but that's all set to change next Saturday August 15th. Per North Korea's official Central News Agency: "The wicked Japanese imperialists committed such unpardonable crimes as depriving Korea of even its standard time while mercilessly trampling down its land with 5,000-year-long history and culture and pursuing the unheard-of policy of obliterating the Korean nation."
The new "Pyongyang time" will see the clocks in North Korea go back 30 minutes, and is seen as a move by Kim Jong Un to garner favour amongst 'anti-Japan' Koreans.
South Korea will continue to use its current time that it says it shares with Japan because it's 'more practical and conforms to international practice'. They expect only minor disruptions with the change, although it doesn't make it any easier for the two nations to get along.
North Korea now joins a handful of countries that aren't separated by the hour, including India, Iran, Myanmar, who are offset by the half hour, and Nepal, which is offset by 45 minutes (which is some pub quiz knowledge that will definitely come in handy one day).
No word yet on whether Ireland will get its own time zone, which will be 'two secs' behind GMT but will actually vary from anything as little as two actual seconds to ten-ish minutes, give or take the traffic.