For me it depends... I lived in Miami- it was quite normal for folks to show up at least 15 minutes late and not think anything of it. (And for a party, if it started at 8, you couldn't show up until 10!)
Here, most of the time, meetings start on time and end on time- if its scheduled for an hour, it lasts an hour. If you wanted it longer, you should have scheduled it longer. Mostly it has to do with the fact that we want to leave work on time! However, mind you, band practice is supposed to start at 7 and we're lucky if we're getting going at 7:15 with everyone there ready to play.
We get frustrated dealing with co-workers in Puerto Rico who definitely show up 15 minutes late, then folks in California who start 10 minutes late and keep the meeting going on for 1/2 an hour after.
When we call Pennsylvania, they're on time but tend to go over time.
When we call China, Germany, Italy, the meeting starts bang on time and ends on time.
When we call Oz, we get varied responses- some on time, some not.
So really, in my case, it all depends.