the day sweden changed from left to right
Dagen H Dagen H (H day), today usually called "Högertrafikomläggningen" ("The right-hand traffic diversion"), was the day on 3 September 1967, in which the traffic in Sweden switched from driving on the left-hand side of the road to the right.[1] The "H" stands for "Högertrafik", the Swedish word for "right traffic". It was by far the largest logistical event in Sweden's history.[2]
Upside down year The most recent upside down year was 1961, and before that where sequentially 1881 and 1691.