...I won't miss - military time. The rest of the world uses military time, something that took a lot of getting used to. I still take half a second upon seeing 16:05 on my clock to decide if it's 4:05pm or 6:05pm.
Up to now this has been a mere annoyance. However today it became full-on issue when I showed up at the airport for my 1pm flight to Tokyo only to find out that I'm 12 hours late. The flight took off last night at 1am!!
The Cathay counter lady pointed out to me that 1:00 was 1am and 13:00 was 1pm. Um yeah, I know, I really do. However a 1am departure seems ridiculous to me for a 3.5 hour flight. And I guess I'm always going to naturally think in American time.
Another reason I'm looking forward to being back in the land of am and pm.