Pedantic, who? Me? Surely not
Actually, you can be if you want to and have time to spare, to wit -
misd-agin said
"That's easy to figure out on a north/south flight, a nightmare on a east/west flight."
Only last night I operated a West to East flight with a high proportion of Muslim passengers who were keen to know the time of Sunrise in our (moving) aircraft. With time to spare, it took about 10 minutes work, and we "nailed" it to within 1 minute. I'd explain how it's done, but someone might label me pedantic!
As an added bonus, we provided them with the direction to Mecca (Qibla) courtesy of FMC direction to waypoint ISLAM. (Notably, airlines like Qatar provide this direction on the passenger map display).
All in a day's work, keeping the folks down the back happy, after all, they pay my salary.
Regards,
Old Smokey