What's interesting is that they chose the date for an anniversary. If they roll the clocks back from 00:00 to 23:30, then they'll be giving 30 minutes more to the previous date - not their anniversary date. Of course, we can't be sure until they announce an actual transition time, or until we get reports after-the-fact about when they actually did it.
From: someone@mearie.org Date: Fri, 7 Aug 2015 11:11:31 +0900 To: tz@iana.org Subject: [tz] North Korea (Asia/Pyongyang) to switch to UTC+8:30
https://en-maktoob.news.yahoo.com/turning-back-clock-north-korea-creates-pyo...
Note that the exact transition time is not specified (0:00 UTC+9:00? 0:00 UTC+8:30? I don't know). I couldn't find any specifics about that.
-- -- Kang Seonghoon | http://mearie.org/ -- Opinions expressed in this email do not necessarily represent the views of my employer. --