Type of visa required? We are flying from Auckland to Beijing on Qantas

and flying out of Beijing to Seoul on Korean Air the same day. We will be in Seoul for a week and then returning to Beijing for a week before flying back to Auckland.
So our itinerary is Auckland-Beijing-Seoul- Beijing- Auckland.
I know we need a visa for the second week, as we will be in Beijing for 7 days, but do we need a visa for the first entry- we will only be in Beijing from 10.30pm to 1.30am (3 hours).