This is all the info I could find for Dragon Ball on New Zealand's TV3 (not to be confused with channels of the same name in Catalonia and Switzerland that also aired Dragon Ball).

* This is based on a scan of The Daily Post newspaper from the week in question, which is the first time "Dragonball Z" appeared on TV listings.Dragon Ball Z: Premiered April 17, 2000*, and aired at 4:30pm Monday-Friday. The broadcast was heavily censored as TV3 had to get a "G" rating, although the channel claimed they received the episodes in this form. From episode 54 (edited numbering) up until, but not including the Boo arc there were also exclusive eyecatches narrated by Dale Kelly. The show was replaced with an American news report the day of 9/11. Every time a new arc ended the show was rerun from the beginning and at a certain point followed by the next arc. From 2001 the Saiyan arc was repeated every year up to 2004. There was a period episodes 1-53 were constantly repeated before TV3 moved on to Funimation's inhouse dub. In 2002 the "Sticky TV" block launched, which Dragon Ball Z was a part of. That same year the Saiyan and Freeza arcs were both rerun twice, then once in 2003 followed by the Android arc, and in 2004 all three arcs were aired again followed by the Cell arc. During the Boo arc after Majin Vegeta blows himself up 16-20 episodes were permanently skipped and never shown during reruns of the arc. After the skipped episodes TV3 picked up from the point known as "the Fusion saga". By 2006 when asked if the show would return TV3 confirmed they no longer had the rights.
Dragon Ball GT: First aired around July 5, 2004 on "Sticky TV" initially in the afternoon like Z, but moved to a morning slot around 2006. As with the US, the first 16 episodes were skipped and replaced with A Grand Problem.
Like the US, Australia and South Africa the Saban dub was shown for the first 53 episodes of Dragon Ball Z followed by Funimation's inhouse dub for the rest of the series and GT.
Regarding GT I am also unsure of its premier date as TV3 schedules started listing the block "Sticky TV" instead of what was aired as part of their line-up. If anyone knows what date GT premiered it would be much appreciated.
For inspiring this thread:
- Thank you Tian and TechExpert2021
- Thank you gohan2k, Captain-Sora, BluezaBladeNZ and ikaos.
Changelog & Additional Thanks
Spoiler: