As per title I am curious why Vodafone NZ still not do not support carrier time / NITZ?
It seems the majority of carriers around the world support it now:
http://en.wikipedia.org/wiki/NITZ
ClockSync on my Android on Vodafone is good workaround but it would be nice if it wasn't needed
https://play.google.com/store/apps/details?id=ru.org.amip.ClockSync&hl=en
https://play.google.com/store/apps/details?id=ru.org.amip.timezoneservice