In New Zealand there are 2 time
zones. The two main islands in New Zealand use NZST
or New Zealand Standard Time which is 12 hours ahead
of UTC or Coordinated Universal Time, while the
far-flung Chatham Islands employ CHAST or Chatham
Standard Time which is 45 minutes ahead of the NZST.
In summer DST or daylight saving time is followed
and all clocks are advanced by an hour. NZDT or New
Zealand Daylight Time is therefore 13 hours in
advance of UTC, and CHADT or Chatham Daylight Time
is 45 minutes in advance of NZDT.
In Antarctica, the Ross Dependency observes NZDT/NZST,
together with the Amundsen-Scott South Pole Station and the
Moreover, there are New Zealand dependencies in the Pacific
Ocean which are located in 2 different time zones because
some of them are located on the other side of the
International Date Line.
In November 2, 1868, New Zealand formally assumed a standard
time to be maintained nationally, and was probably the first
nation to do so. This standard was famous as the NZMT or New
Zealand Mean Time.
During WWII in 1941, clocks were ahead by 30
minutes, making New Zealand twelve hours in advance
This modification was made undeviating by the 1945
Standard Time Act from 1946, during which point the
meridian of 180°E was made the foundation for the
tie in New Zealand. New Zealand Standard Time stayed
30 minutes ahead of NZMT, and 45 minutes ahead in
the Chatham Islands.
In the latter part of the 1940s the development of
the atomic clock led to many laboratories to make
use of atomic time scales.
The UTC or Coordinated Universal Time was a new time
scale which by 1972 was adopted globally.
This was founded on the indications of atomic
clocks, periodically updated following the time
fluctuations in the rotation of the earth by the
deletion or addition of seconds also known as leap
The 1974 Time Act defines the NZST or New Zealand
Standard Time as twelve hours ahead of UTC.
By 2007, DST in New Zealand is followed from
September’s last Sunday until April’s first Sunday.
Beginning in 1909, the Honorable Sir Thomas Kay
Sidey declared a Bill each year to wind the clocks
ahead by one hour starting September up to March the
next year and the 1927 Summer Time Act won:
November’s first Sunday to March’s first Sunday.
This turned out to be so unpopular that the 1928
Summer Time Act changed this to a 30 minute shift
from October 14, 1928 to March 17, 1929.
Afterwards, the 1929 Summer Time Act fixed this 30
minute shift to run from October’s second Sunday to
March’s third Sunday.
It was in 1933 that the period was lengthened from
September’s first Sunday to April’s last Sunday. This went
on until World War II, when emergency rules in 1941
lengthened daylight saving to extend throughout the year
with yearly reapplications until the 1945 Standard Time Act
which made the desertion of NZMT lasting in 1946, which
resulted in 180° to become the longitude base. This was then
NZST or New Zealand Summer Time which was later changed to
New Zealand Standard Time.