New Zealand standard time
The establishment of New Zealand standard or mean time had brought a new social consciousness. But time did not stand still. In 1941 clocks were advanced half an hour to 12 hours ahead of Greenwich, to allow for greater use of sunlight during the war, and in 1945 the Standard Time Act made this permanent. Chatham Islands time was set 45 minutes in advance of New Zealand standard time.
In 1884 Greenwich Mean Time became the international standard, with Greenwich in England as the prime meridian. A system of international time zones was established, and in 1928 Universal Time was brought in.
Atomic clocks, which became available in the 1950s, allowed more accurate calculations, and a new scale called Co-ordinated Universal Time was adopted in 1972. Variations were adjusted with the addition or deletion of leap seconds. Under the Time Act 1974 New Zealand standard time was defined as 12 hours in advance of Co-ordinated Universal Time.
Daylight saving: ‘summer time’
Early in the 20th century the member of Parliament for Caversham, Thomas Sidey, advocated putting the clocks forward in summer to allow for after-work recreation, such as gardening and sport, in daylight. He was finally successful in 1927, when the clocks were advanced by an hour over summer.
From 1928 until 1941 the advance was only half an hour. War regulations in 1941 and the new act of 1945 advanced New Zealand standard time by half an hour for the whole year, and ‘summer time’ disappeared.
The idea was revived in 1974 when an advance of one hour in summer was trialled. There were complaints from dairy farmers, who had to start milking earlier to meet the schedule of the milk trucks. But generally the move was supported, and daylight saving in summer has since become established, although the start and finish dates have been gradually extended due to public demand. Since 2007 daylight saving time has started at 2 a.m. New Zealand standard time on the last Sunday in September, and ended at 2 a.m. (standard time) on the first Sunday in April.
Time keeping in the 2000s
Responsibility for keeping New Zealand time rested with the Colonial Observatory until 1926, when the service was taken over by the Department of Scientific and Industrial Research (DSIR). Astronomical observation was still used, checked by overseas radio signals. However, in 1962 clocks based on the electrical oscillations of quartz crystals were adopted. They kept time accurately to within one-quarter of a second. Subsequently the vibrations of the caesium atom were used, giving an error of no more than one second in 3,000 years.
In 1992 the DSIR was disbanded, and responsibility for New Zealand time moved to the Measurements Standard Laboratory of the Institute for Industrial Research and Development. The official time was kept by three caesium atomic clocks linked with Co-ordinated Universal Time through the Global Positioning System (GPS). The laboratory transmits six ‘pips’ every hour (the sixth pip marking the hour), to the National Radio Station, and through a telephone service.
Just a second
In 1967 the caesium atom, rather than the earth's movement, became recognised internationally as the basis for the unit of time, because it emitted radiation at a very stable frequency. A second was defined as 9,192,631,770 oscillations or cycles of the caesium atom's resonant frequency. This is rather more accurate than the old count of ‘one hippopotamus, two hippopotamus’.
Time and modern society
After the 1960s, wind-up wristwatches were replaced by battery-run models. From the 1970s many people opted for digital displays rather than the traditional moving hands.
Timing at sporting events has become more precise. Running or swimming times are recorded to within one-hundredth of a second, rugby games are timed to the second and a hooter sounds when each half is over. Like everyone else, New Zealanders are more time-bound than ever – cellphones, computers and radios, as well as watches and clocks, all signal the hour, where once it was the chime of a bell that did so.