12 is 0, that's how analog clocks display time, and that's the only way to make sense of the strange numbering (12->1->2-...>11? What?). Maybe because Romans d

12 is 0, that's how analog clocks display time, and that's the only way to make sense of the strange numbering (12->1->2-...>11? What?). Maybe because Romans didn't have 0? Apparently not, the reason comes from before them, but analog clocks are commonly written with Roman numerals so it's a way to remember this.