Perhaps 10:11 pm was early. If I remember when I was in Wellington, a noise compliant could be lodged after 10 pm.

Honestly I think this is a reasonable time to stop, in particular with "salutes" (loud single bangs)

By the way, I'm in New Plymouth. I've talked to several horse owners over the years. They have plenty of stories of terrified animals, and their injuries.

From SPCA in New Zealand:

"SPCA advocates for a ban on the private sale and use of fireworks in New Zealand due to the distress and harm they cause to animals.

SPCA advocates that fireworks, pyrotechnics and gas-fired explosions should never be permitted to be used at events involving animals due to the distress they cause animals.

Fireworks cause significant fear and distress to animals, compromising their welfare. SPCA is also concerned that people directly target wildlife and other animals who are injured or killed deliberately with fireworks.

SPCA is concerned about the impact fireworks have on wildlife in the vicinity. Animals change their behaviour in response to loud and abrupt noises and this can lead to physical injury and disruption of feeding, abandonment of young, stress and mortality, all of which are signs of mental suffering.

SPCA supports the use of fireworks in controlled and notified public displays.

Our organisation acknowledges that many New Zealanders include firework displays when celebrating special occasions such as Matariki, Diwali, Chinese New Year, and Guy Fawkes and we are supportive of controlled and notified public firework displays."