Fun fact: military time, or astronomical time, is the most commonly used time keeping notation in the world, what with its sensible unambiguity and all. Practicing medicine? Programming a computer? Launching F-18s off an aircraft carrier? Nothing beats measuring time from midnight to midnight.
Oddly enough, though, there aren’t many analogue clocks that operate with a twenty-four hour mechanism, so visual artist Tauba Auerbach built one. The 24-Hour Wall Clock ($120) ships from the US, has Roman numerals, though, also oddly, doesn’t follow the IIII convention. See? Breaking even more ground.