I raced it in career mode. I was surprised at the length. I usually have my setting.at 50%, so I found myself racing a 12 hour race in real time.
I reset the length to 2 hours and learned a lot racing it. The transition from light to night to dawn was worth it. I think career ,ode let's you do it once per season. The track is challenging, but fun enough to justify taking the time to learn.