Time zones are hard

Having spent a painful fraction of my life fighting time zones, I loved this from The Diplomad:

As the party was winding down, I slid over to one of my Japanese contacts and kidded him about the date, "You have guts throwing this event December 7."
He seemed perplexed, "We decided to hold it today instead of tomorrow, because of American sensitivities about that day."
Now I became the perplexed one, "What's so sensitive for us about December 8?"
My Japanese friend looked at me as though I were the biggest ignoramus on the planet, "You know, Pearl Harbor attack day."

Anyone who thinks that times and dates are straight forward, either a) has never tried to work internationally or b) is in the military and works off Zulu Time where ever they are on the planet.

The lesson I took from this is that no matter how simple you may think a concept is ("what day is this?") you should realize that there's someone of consequence and rationality who has a different opinion from you.