The clock in Trainz is pretty accurate. I will sometimes set the clock to the actual time based on my room clock. It's a bit tricky to get the two to sync up because of the delay when Trainz loads, but with a little fiddling around, like subtracting a couple of minutes during the clock setup, I got the two to be pretty much dead on (maybe only a couple of seconds difference).
With the accurate clock, I was able to tell what real time it was because I am on a very strict schedule of every 3-hours for some medication I need to take. It was also pretty neat too driving with the real time because I started in the afternoon at 2:00, and ended at 9:00. The sun went down, the stars came out, and the city lights came on. It looked realy cool as the lighting changed through out the day.
John