Roman numeral 4 is typically represented as IV, but did you know that on clock faces, it is often shown as IIII? One theory suggests that King Charles V of France found IV to be unlucky, as it reduced his title of 5 (V) by 1 (I). Another reason is that IIII is more visually balanced on clock faces with symbols like VI and VIII. This tradition dates back to the late 14th century in Wells Cathedral and continued until the 17th century. The unexpected history behind this simple notation is a fascinating example of how seemingly small details can shape our daily lives.
https://museum.seiko.co.jp/en/knowledge/trivia02/