If there is any "cultural" aspect of the Jewish People that you should know, it's Jewish Standard Time (JST). I swear I hear this phrase at least twice a week, and I live in a very small community. I can only imagine its effects in the larger communities!
In my Jewish encounters, I've found that JST translates to 5-15 minutes late. However, I was listening to a shiur (lecture) about telling the truth and misleading people. The example used throughout the discussion was JST and a Jewish wedding. I'm paraphrasing from memory, but "Don't write 6:30pm on the wedding invitation if you plan to actually be married at 6:30pm, but your community would understand '6:30pm' to mean '8pm' in JST. You need to take JST into account when giving instructions to people."
Being a relatively punctual person (though getting lost frequently might make me a liar here), I cannot fathom that someone would read time as being an hour and a half later. Granted, maybe that's wedding/simcha specific...but still. Really? That's just impressive, and not in the good way.
Have any interesting JST encounters?