24-hr transit visa from Manila to Amsterdam via Xiamen

Hi,

My son will be travelling from Manila to Amsterdam and back, with a layover at Xiamen airport:
Outbound: 19 Dec 2017, Total layover at Xiamen airport = 14 hours 25 mins
Inbound: 06 Jan 2018, Total layover at Xiamen airport = 11 hours 35 mins

He holds a Philippine passport and a permanent Belgian residence card. Is the 24-hour direct transit applicable for both of his outbound and inbound flights?

Thanks and regards.