Left Luggage Matters. I'm arriving Baiyun Airport at 11pm.

Hi there... I plan to stay the night and do some travelling the next day before I board my next flight at 9pm. Since I have some heavy luggages with me, it would be very inconvenient to bring them around the city. Could you tell me where can I locate the left luggage and how much it cost? Will it still be offering its services around 12am (after I collect my luggage and pass immigration)?