You go: "What time is dinner?". "8 PM". "OK" (shows up 8:30-9)
You go: "What time is dinner?". "8 PM. Please try to be punctual I have stuff to do in the morning". "OK" (shows up 8:15-8:30)
More or less the same thing happens at universities (at least that I know). Lectures are at full hours, but start at 15 past and last 45 minutes. That means that you have time to move from building to building and/or take a break.
Sometimes you'll see graduate seminars with the mention (sharp!!) next to the time, it means that since PhD students don't have many lectures, the seminar can start at full hours, because they probably have nothing to do just before that.
Obviously punctuality depends on the context, ranging from 15 minutes late for university, to 30-60 for concerts or dinners, to some crazy stuff for clubbing (free entry before midnight to try to get someone in early, even though the DJ is supposed to start at 10PM).
The universities thing is interesting, I've attended and seen several in the Pacific Northwest, USA. They universally ran at exact times, and ended with a buffer, such as 10 minutes until the next timeslot. e.g. 10:00 am - 11:50 am for a 'two hour' lecture, 3:00 pm - 4:20 pm for a twice a week '3 hours per week' lecture and similar. They would typically start on time or shortly after, and tardiness was frowned upon.
Hilariously, when classes were right after one another this sometimes meant down the hall or the building across the street and plenty of leisure time, or it could mean corner to corner on a huge campus and having to leave early, arrive late, or run. In this sense the buffer times didn't solve the problem either.
You go: "What time is dinner?". "8 PM". "OK" (shows up 8:30-9)
You go: "What time is dinner?". "8 PM. Please try to be punctual I have stuff to do in the morning". "OK" (shows up 8:15-8:30)
More or less the same thing happens at universities (at least that I know). Lectures are at full hours, but start at 15 past and last 45 minutes. That means that you have time to move from building to building and/or take a break.
Sometimes you'll see graduate seminars with the mention (sharp!!) next to the time, it means that since PhD students don't have many lectures, the seminar can start at full hours, because they probably have nothing to do just before that.
Obviously punctuality depends on the context, ranging from 15 minutes late for university, to 30-60 for concerts or dinners, to some crazy stuff for clubbing (free entry before midnight to try to get someone in early, even though the DJ is supposed to start at 10PM).