Clocks not changed but standard time zone is changed
When local standard time is about to reach Sunday, March 31, 1991 at 2:00:00 AM the standard time zone offset is changed from UTC/GMT +3 hours to UTC/GMT +2 hours and at the same time daylight saving time started
When local daylight time is about to reach Sunday, September 29, 1991 at 3:00:00 AM clocks are turned backward 1 hour to Sunday, September 29, 1991 at 2:00:00 AM local standard time instead
