The 24 hour clock does make more sense, but in the US people who use it are either military or weird.
I grew up in a military family. My dad, a navy man of 20 years, uses 24 hour clock on everything. He gets mildly annoyed whenever it is called military time.
Semi-related: the guys at Bible Reloaded were reviewing a movie that they expected to be 1 hour and 15 minutes long and were dismayed to learn was almost 2 hours long. What gives?DVD label: "Runtime: 115 minutes"