Travelling to Shanghai directly via Hong Kong

Hi There

We are going to Shanghai as tourists directly via Hong Kong next Saturday. Air New Zealand to HongKong in transit then to Shanghai by Cathay Pacific arriving 4th May. We are leaving 9 May for Hong Kong where we will stay for 7 days leaving 16 May to return to Auckland. We are FIT's & both have valid New Zealand passports.
Our information is that a 30 day visa will be granted upon our arrival in Shanghai & we would appreciate your advice on this.

Many Thanks

Keith Stead