Well... runway numbers are, apparently, based on the direction (in degrees) that the runway faces. So... what's zero? Due North? Okay... is it True North or Magnetic North? At Kansai International, a huge plan of which is hanging in front of me at this moment, the runway is at a precise 51-degree angle to True North, so you'd think that it would be numbered 05, given that only the first 2 digits of the three-(possible)-digit number are used. But no, it's actually 06. I assume that this is because the runway is at a 57-degree, 46-minute, 42-second angle to Magnetic North, which makes one wonder why they aligned it perfectly at 51-degrees with True North. Anyway... can someone please explain how exactly runways are numbered?