Care to comment where this leaves us? From NZ History net, an "official NZ Govt site". 
 "In contrast to its entry into the First World War, New Zealand acted in its own right by formally declaring war on Germany on 3 September (unlike Australia, which held that the King's declaration, as in 1914, automatically extended to all his Dominions).  

 Officially, New Zealand's declaration of war was simultaneous with Britain's – as it was held to exist from the expiry of the British government's ultimatum to Germany to withdraw from Poland (9.30 p.m. New Zealand standard time, 11 a.m. British summer time). In fact, ministers and senior officials waited on formal advice of the expiry of the ultimatum, and Britain's declaration of war on Germany, before taking any action. It was not until 11.30 p.m. that the acting Prime Minister, Peter Fraser, issued a statement confirming that New Zealand was at war:"