When To Book Purchase Under GST

Suraj Gupta (Accountant) (44 Points)

10 January 2018  
I am registered Dealer in Delhi and I got my goods on 03/01/2018 from Registered Dealer of Madhya Pradesh along with GST Invoice dated 30/12/17.i.e. my invoice
reciept date is 03/01/2018, when should I record my purchase in my books of accounts. 03/01/18 or 30/12/17, and how will to match it in GSTR - 2.