Earlier check in at airport to exceed the 72 h transit time

Hi guys, I will be traveling from Hongkong to Guangzhou (15th September; arriving time: 9:25 PM) and then to Amsterdam (19th sep; leaving time: 0:55 AM).

I want to apply for the 72h transit visa. Since the 72 h calculation starts with the following day (16th) I'm planning to go through the security check at the airport on 18th before 9 PM and wait until my flight on 19th 0:55 AM.

Do u think it's possible during the 72h free transit?
Thx in advance
Dun from Berlin