Arriving 1 1/2 to 3 hours late to any event, regardless of its importance when you are from any middle eastern country. Some instances are more severe, specifically in Saudi Arabia, where Arab Time is standard time and arriving 3-4 hours late for an event is expected. Confusion occurs often for expats and immigrants living in the west.
"The party starts at 8pm - or 10pm arab time",
"oh hi, you're here early!"
"Ah, yes the invite said 8pm"
"mmm, yeeeeah, we just assumed everyone would be on Arab Time"
(In western countries)
"Come over at 8pm"
"Arab Time or American Time?"
"LOL, make it 9pm American Time"