It doesn't matter... to anyone in UK, where its been decided it will be treated as foreign currency
. Sry, cant resist a bit of sniggering at all this, you guys across the pond kicked over taxation but seem to be left with the oddest, harshest tax system around - that's some achievement.
I actually wanted to point out the options are pretty acedemic. They wont care if you owned it at 4:30pm or 5:20pm, they'll just want a value noted for the days market price. if its over midnight... that might cause you some problems if there's a sudden spike or crash. I'd confidently predict any judge would rule option two, when you mined/purchased as you done so with the full expectation that the confirmations would occur. Its also the first point at which ownership can be said to occur.