North Korea

Time travel is a normality for North Koreans. In 2015, a special time zone called the "Pyongyang zone" was established.

An excerpt from the article 24 facts about North Korea

In this zone, there was a shift of half an hour backward relative to South Korean time. The Korean government's brilliant idea must have backfired, however, because less than three years later, watches were moved forward again by half an hour, and the same time zone applies in both Koreas.