Capital: Wellington, Longitude 174°E 46´ Latitude 41°S 17´

Local mean time was observed up to 1868. Standard Time Meridian, 172E30, was adopted on 2 November 1868 (New Zealand Mean Time, 11 hours 30 mins in advance of Greenwich Mean Time).

Summer time 1927 was observed for one year only when clocks were advanced one hour (New Zealand Summer Time, 12 hours 30 mins ahead of GMT. At commencement clocks were advanced 1 hour at 2:00 am (Mean Time) to 3:00 am (Summer Time). At the conclusion, clocks were turned back at 3:00 am (Summer Time) to 2:00 am (Mean Time).

Summer time was observed during 1928-1945 when clocks were advanced only 30 mins, 12 hours ahead of GMT. At commencement clocks were advanced 2:00 am (Mean Time) to 2:30 am (Summer Time). At the conclusion, clocks were turned back at 2:30 am (Summer Time) to 2:00 am (Mean Time).

Summer time periods

Started	Period	Finished	Advanced
1927	6 November to 4 March	1928	one hour
1928	14 October to 17 March	1929	30 mins
1929	13 October to 16 March	1930	30 mins
1930	12 October to 15 March	1931	30 mins
1931	11 October to 20 March	1932	30 mins
1932	9 October to 19 March	1933	30 mins
1933	8 October to 29 April	1934	30 mins
1934	30 September to 28 April	1935	30 mins
1935	29 September to 26 April	1936	30 mins
1936	27 September to 25 April	1937	30 mins
1937	26 September to 24 April	1938	30 mins
1938	25 September to 30 April	1939	30 mins
1939	24 September to 28 April	1940	30 mins
1940	29 September continuing to 31 December	1945	30 mins

From 1 January 1946, what was formerly known as New Zealand Summer Time, 12 hours in advance of GMT, became New Zealand Standard Time, 12 hours in advance of GMT. The abbreviation for both these meridians is NZST and both correspond to the longitude of 180E00, 12 hours in advance of GMT.

Daylight time was introduced in 1974, for the periods listed below. At commencement, clocks were advanced 1 hour at 2:00 am (New Zealand Standard Time: NZST) to 3:00 am (New Zealand Daylight Time: NZDT), corresponding to a longitude of 195E00, 13 hours ahead of GMT. At the conclusion, clocks were turned back at 3:00 am (NZ Daylight Time) to 2:00 am (NZ Standard Time).

NZ Daylight time (NZDT) periods

Started	Period	Finished	Advanced
1974	3 November to 23 Feb	1975	one hour
1975	26 October to 7 March	1976	one hour
1976	31 October to 6 March	1977	one hour
1977	30 October to 5 March	1978	one hour
1978	29 October to 4 March	1979	one hour
1979	28 October to 2 March	1980	one hour
1980	26 October to 1 March	1981	one hour
1981	25 October to 7 March	1982	one hour
1982	31 October to 6 March	1983	one hour
1983	30 October to 4 March	1984	one hour
1984	28 October to 3 March	1985	one hour
1985	27 October to 2 March	1986	one hour
1986	26 October to 1 March	1987	one hour
1987	25 October to 6 March	1988	one hour
1988	30 October to 5 March	1989	one hour
1989	8 October to 18 March	1990	one hour
1990	7 October to 17 March	1991	one hour
1991	6 October to 15 March	1992	one hour
1992	4 October to 21 March	1993	one hour
1993	3 October to 20 March	1994	one hour
1994	2 October to 19 March	1995	one hour
1995	1 October to 17 March	1996	one hour
1996	6 October to 16 March	1997	one hour
1997	5 October to 15 March	1998	one hour
1998	4 October to 21 March	1999	one hour
1999	3 October to 19 March	2000	one hour
2000	1 October to 18 March	2001	one hour
2001	7 October to 17 March	2002	one hour
2002	6 October to 16 March	2003	one hour
2003	5 October to 21 March	2004	one hour
2004	3 October to 20 March	2005	one hour
2005	2 October to 19 March	2006	one hour
2006	1 October to 18 March	2007	one hour
2007	30 September to 6 April	2008	one hour
2008	28 September to 5 April	2009	one hour
2009	27 September to 4 April	2010	one hour
2010	26 September to 3 April	2011	one hour
2011	25 September to 1 April	2012	one hour
2012	30 September to 7 April	2013	one hour
2013	29 September to 6 April	2014	one hour
2014	28 September to 5 April	2015	one hour
2015	27 September to 3 April	2016	one hour
2016	25 September to 2 April	2017	one hour

Note:
NZ standard time (NZST) is 12 hours ahead of GMT.
NZ daylight time (NZDT) is 13 hours ahead of GMT.

Note: On 30th April 2007, the Minister of Internal Affairs announced that New Zealand will be observing daylight time from the last Sunday in September through to the first Sunday in April the following year.

Time Change information was researched by Carol Squires.

References: NZ Dept of Internal Affairs, NZ High Court Auckland Library, Auckland Public Library, New Zealand Herald, and Astrological Society of NZ Inc Journal of the Seasons, Vol 2, 1975.