flying during dragon boat holiday

I am planning on being in Xian for May 28, flying to Datong May 29 & spending May 30 sightseeing in Datong. I just saw that may 28-30 is a holiday. how will this affect air travel? does the high speed train go to Datong yet? how will the holiday affect my sightseeing in Xian? also in Datong? will things shut down these 3 days? will there be activites etc happening that are normally not available ?