NBC Sports has been playing the races on a delay most times and with the addition of the time-of-day offset between the USA and NZ, it's sometimes hard to figure out where to find the races to record on your DVR. Add to this the lack of detail provided by NBC Sports in the online cable-guide it is hard to tell which race they are actually playing, so in the US it is quite a challenge.
(Real-time online race streaming is blocked in the USA. See comments about VPN below)
Here is what I THINK I figured out (ET = Eastern Time USA):
Prada Semi Finals
Thu, 28 Jan -> Airs Fri, 29 0030hrs ET
Fri, 29 Jan -> Airs Fri, 29 2200hrs ET
Sat, 30 Jan -> Airs Sun 31 1400hrs ET
Mon 1 Feb -> Airs Mon 1 2230hrs ET