2 days transit after visa expire in Shenzhen

I’m danish and have a student visa there will expire the 31st of July. I’m leaving China the 29th of July but want to come back the 6th of August to catch my flight to Europe on the 8th of August. I’ll land at SZX at 2 am. Will the visa center be open? And do you expect there will be problems when I have already had a Chinese visa?