On November 2, 1868, New Zealand officially adopted a standard time to be observed nationally, and was perhaps the first country to do so. It was based on the longitude 172° 30' East of Greenwich, that is 11 hours 30 minutes ahead of Greenwich Mean Time. This standard was known as New Zealand Mean Time.
During the Second World War, clocks were advanced half an hour in New Zealand for the duration of the War, starting in 1941 (12 hours ahead of Greenwich Mean Time). This advance of time was made permanent in 1946 by the Standard Time Act 1945. The Act provided that the time at the meridian 180°E was adopted as the basis for New Zealand Time. The new Act put into effect New Zealand Standard Time which was permanently half an hour ahead of New Zealand Mean Time as determined in 1868 and 12 hours in advance of Greenwich Mean Time or Universal Time. (The Chatham Islands was 45 minutes in advance of New Zealand Mean Time under the new Act).
In the late 1940s the development of the first atomic clock was announced and several laboratories began atomic time scales. A new time scale known as Coordinated Universal Time (UTC) was adopted internationally in 1972. This was based on the readings of atomic clocks but updated periodically in accordance with time variations in the earth's rotation by the addition or deletion of seconds (called leap seconds). Fifteen leap seconds have been added to our time since 1972.
The Time Act 1974 defines New Zealand Standard Time, as meaning the 12 hours in advance of Co-ordinated Universal Time.
Daylight Saving Time
The Summer Time Act 1929, which was later replaced by the Time Act 1974, gives power to the Governor-General to declare a period which Daylight Time is to be observed by Order in Council. Under the Act, Daylight Time is fixed as a one hour advance on New Zealand Standard Time.
The Summer Time Act of 1929 provided for Daylight Time to be observed in New Zealand from the second Sunday in October to the third Sunday in March of the following year. Clocks were set half an hour in advance during that time. In 1933 the period was extended from the first Sunday in September to the last Sunday in April of the year following. This continued until World War II when in 1941, the Summer Time period was extended by emergency regulations to cover the whole year. This change was made permanent in 1946 with the Standard Time Act of 1945.
The New Zealand Time Order 1975 fixed period of observance from the last Sunday in October each year to the first Sunday in March of the year following.
In 1985, after 10 years experience with Daylight Time, a comprehensive survey was undertaken by the Department of Internal Affairs. Public attitudes towards Daylight Time and its effects on work, recreation and particular groups of people in society were surveyed. The results of the survey demonstrated that 76.2% of the population wanted Daylight Time either continued or extended.
The survey also concluded that opinion on the topic differed little between sexes, and that support for Daylight Time was generally higher in urban centres. Support for shortening or abolishing Daylight Time was always in the minority in the areas surveyed.
In 1988 as a consequence of the survey and further feedback from the public, the Minister of Internal Affairs arranged for a trial period of extended Daylight Time to be held in 1989/90 from the second Sunday in October to the third Sunday in March. The Minister invited the public to write to him with their views on the five week extension.
Today, under the new Daylight Time Order 1990, it declared that Daylight Time would commence at 2.00am Standard Time on the first Sunday in October each year (changes from 2am ST to 3am DST) and would cease at 2.00am Standard Time on the third Sunday in March of the following year (changes from 3am DST to 2am ST).