The Department of Internal Affairs administers
daylight saving, and its website includes this
short history of the evolution of daylight saving
in New Zealand.
The Measurement Standards Laboratory is
responsible for establishing the New Zealand
standard time. This page explains how they do this,
and how they communicate time throughout New
Zealand.
More suggestions and sources
Landes, D. S. Revolution in time: clocks and
the making of the modern world. Cambridge,
Mass.: Harvard University Press, 1983.
Pawson, Eric. ‘Local times and standard time in
New Zealand.’ Journal of Historical
Geography 18, no. 3 (1992): 278–287.
‘Timekeeping in New Zealand.’ Alpha 36
(October 1983).