/chinese/hrc/hindex.asp, you can find out that there is a horse race that day and the start time. If the racecourse is not full, you can enter at any time.

I'm sorry for reading the wrong question. Then I called my friend who loves horse racing. Sunday 3 1, Sha Tin Ri Marseille 1 1. Go in at 4: 30 and you should be able to see the last three or two races. What you said above is basically correct.