For smaller networks and end users, the best NTP servers to use are the ones supplied by your service provider or ISP.
Many ISPs have 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 NTP servers, based on the servers below.
There are four stratum 1 NTP servers provided by 
.nz Registry Services (NZRS) for network operators based within New Zealand. They are operated by NZRS Limited, a wholly-owned subsidiary of 
InternetNZ.
It is not a public network but is covered by an Acceptable use policy. These timeservers are provided primarily for network operators based within New Zealand and peripatetic users who are ordinarily based in NZ.
The host names s[1-4].ntp.net.nz can be used for:
The host names p[1-4].ntp.net.nz can be used for:
The following devices are not allowed:
All four are Sonoma D12 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. They are not actively synchronised to each other. more
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).
The servers are publicly available to all connections from within NZ. NTP requests from outside NZ are geo-blocked.
They are FreeBSD-based servers synchronised to the New Zealand time standard UTC(MSL) - which is based on HP5071A caesium clocks - using a 1 pulse per second signal. The servers are typically stable with respect to UTC(MSL) to around 1 microsecond, but NTP limits the accuracy for remote clocks/clients to milliseconds. A load-balancer collects the individual servers into a 'pool' which provides a single point of access. 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.
Scientific study from 1999 on the topology of the country's main NTP servers (note that GPS is much more widely available now)3 pages link to NTPServers:
