transit visa longer than 72 hours from arrival and departure. I am Ukrainian.

Hi, I fly from Bali via Shanghai to Germany. I arrive on 4 at 7am and fly back on the 7th at 2 am. The time between my arrival and departure less then 72 hours, but if they calculate 00 00 the following day then its a bit more. The guys in immigration say that the following day is day after your arrival. Where is the truth? Do they calculate from the arrival time or the following day. At 00 00 on the 4th I will still be in Bali, how can they stay counting the transit? Please help to clarify...