For smaller networks and end users, the best servers to use are the ones supplied by your service provider or ISP.
Many ISPs have NTP servers for their customers:
or you could try querying your ISP's DNS servers with ntp or ntp1.
There is a pool of servers at nz.pool.ntp.org, which provides RoundRobin DNS access to publicly accessible NTP servers that have agreed to be part of the pool.
First: be nice! You shouldn't synchronise to a stratum 1 server for your small network -- if everyone did that then the server would need too much bandwidth. For example. NetGear? hard-coded a public NTP server into some of their consumer products, which eventually ended up using hundreds of Mbits/second of the university's bandwidth, even after they were forced to shut down the server.
If you are running a substantial network, you should install your own Level 2 NTP servers, based on New Zealand standard time as described below.
The standard for time in New Zealand is maintained by the Measurement Standards Laboratory, part of Industrial Research Limited. MSL runs several public NTP servers that are referenced to UTC(MSL).
They are FreeBSD-based servers that are directly connected to their master HP5071A caesium clock. more
There are three stratum 1 NTP servers provided by .nz Registry Services (NZRS) for network operators based within New Zealand.
All three are Symmetricom S300 NTP servers, each connected to a differential GPS antenna on the roof and each with a rubidium oscillator to provide a stable clock in the event of an issue with the GPS signal. more
Most universities restrict access to their NTP servers, however some are publicly accessible:
For a long time WaikatoUniversity had public NTP servers. They are still available but no longer publicly accessible.
3 pages link to NTPServers: