The term dairy came into common usage in New Zealand English to describe small shops by the late 1930s.
[2][3] The distinction between dairies, superettes and grocery stores has grown increasingly blurred in New Zealand English, a fact acknowledged by the Liquor Licensing Authority in 1991, and by the Law Commission.
Contributing factors to this blurring of meanings include the deregulation of trading shop hours on Sundays, ambiguity over alcohol sales laws (see § Sales of alcohol and legal highs below), and the abolition of restrictions on types of goods permitted to be sold by dairies.
[4] The Law Commission summed up the ambiguity as follows: Traditionally, a dairy was a small shop in a suburban area that sold goods such as butter, milk, bread and confectionery.
As dairies must remain open long hours to stay profitable, they are almost always family-run businesses that utilise family members to run the shop.