hong kong stop. I have a dutch passport. is that possible?

i like to travel from ho chi minh to guangzhou with a transfer in hong kong (ho chi minh -> hong kong -> guangzhou) and stay in guangzhou for 72 hours and then fly to manila (phillipines) and then back to holland.also if i arrive on friday night 5/6/2015 21.30. when do i need to be gone. on monday 8/6/2015 before 21.30? or before monday before 00.00.