In practice mode, GT5s time cycle is much faster than in real life. From dawn to dusk it's about 30 minutes.
Not sure about 24 hours... Haven't reached the events.
That would be nice to see {dawn}
In both of the 24's I've raced, both A+B Spec,
it rained @ dawn.
The though was that the race started at 2 pm.
If it does, it's in the fall or winter, as 4hrs into the race both times,
it was dark.
What should have been dawn happened @ hr 14.
The 24 hr timing seemed pretty close.