Ohinemuri Regional History Journal 42, September 1998


On 2 November 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 172o 30_ East of Greenwich, that is, 11 hours 30 minutes ahead of Greenwich Mean Time. This standard was known as New Zealand Mean Time.

Greenwich Mean Time was the mean time determined by observations of the sun at longitude measuring 0o east and west at Greenwich Observatory, England, that is Mean Time for the Greenwich Meridian.

In 1884, at an international conference in Washington DC, the Greenwich meridian was adopted as the prime meridian, with all time reckoned to the longitude east or west of the prime meridian (Greenwich). The development of a system of standard time zones based on 24 meridians each 15o or one hour apart as measured from Greenwich, was prompted by the expansion of railroads. Time differences between communities became a critical factor in the running of railroads over great distances such as in Canada and the United States.

In 1928 the term Universal Time (UTO) was adopted internationally as a more appropriate term than Greenwich Mean Time for the basis of an international standard of time. This was again prompted by expansion of rail transport and also shipping and air transport. But the term Greenwich Mean Time persisted in common usage, probably because at first the two were the same.

During the Second World War, clocks were advanced half an hour in New Zealand for the duration of the War from 1941. This advance of time was made permanent in 1946 by the Standard Time Act 1945. The Act provided that the time at the meridian 180oE 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 Co-ordinated Universal Time 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 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.

A new Time Act was passed in 1974 which empowered the Governor-General to declare a period during 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 public response to a trial period of Daylight Time in 1974/75 was generally favourable and the New Zealand Time Order 1975 fixed the period of observance from the last Sunday in October each year to the first Sunday in March of the year following.

In 1985, after ten years' experience with Daylight Time, a comprehensive survey was undertaken by the Department of Internal Affairs. Public attitudes towards Daylight Time and its effect on work, recreation and particular groups of people in society were surveyed. The results of the survey demonstrated that 76.2% of the population either wanted Daylight Time continued or extended. The survey also concluded that opinions on the topic differed little between the sexes, and 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. Again the public response was generally favourable and a new Daylight Time Order was made in 1990. It declared that Daylight Time would commence at 2.00 am Standard Time on the first Sunday in October each year and would cease at 2.00 am Standard Time on the third Sunday in March of the following year.

[Information provided by Department of Internal Affairs.]