Huh, I didn't realize 24 hour time was so scarcely used in the US.
We use the 24 hour time here in Portugal (in every digital clock, written information, etc), but it also threw me off. 9-5 is a common linguistic expression, while 9-17 reads "nine to seventeen" to me. Maybe "9-17h" would work better.
In the UK it's not that it's used scarcely, it's that the expression is usually written as "9-5".
Hmm, yeah... In Greece we use it interchangeably with the 12-hour time, but whenever my brain sees 17, it just translates it to "5", so the expression made sense. Then again, I skipped that part in the article and only saw it in the comments, so I may have already been primed for it.
As someone from the US that uses a 24 hour clock everywhere, I've gotten many questions and weird looks.
I thought the OP was rating himself 9 on a scale of 1-17!