24h transit visa overstay

Indeed, your itinerary:

Europe - Zhengzhou - Guangzhou - Manila

Is eligible for 24 hour visa free transit and you do not need any kind of visa. You will just print out your flight tickets because of easier handling at check-in in Europe and later upon your arrival in China. You should just carefully count your transit hours in China and they are counted from your scheduled arrival in Zhengzhou until your departure from Guangzhou. If that amount of hours does not exceed 24 hours, you are eligible for 24 hour visa free transit.

Now, if it happens that one of your flights is delayed and you end up spending more than 24 hours in China, an airline will perform all the necessary formalities, including your registration and similar and you will be treated as if you did not breach any rule, but you will not be considered to be in 72/144 hour visa free transit. In any case, you will not bear any consequences, so travel with absolute peace of mind.

One more detail... When you land in Zhengzhou, the first thing you will do is to approach transit counter where you will present your flight tickets and apply for a temporary entry permit to be allowed to proceed for your flight to Guangzhou that will be a domestic one. This application is formality, it is free of any charge, but is necessary. Enjoy your journey.

hey, thank you very much for your help Borut!