I think this is as far as I will go with my trips ever - planning trip to New Zealand! It just came to my mind to go there, I guess I watched travel channel and caught my attention. I know it is not a usual way to pick a trip. Usually people are going to destinations they dream off and I picked mine cause of curiosity. I think I missed this fact on TV, but when is the best time to go to New Zealand?
I have no idea why are you explaining yourself that much; New Zealand is a beautiful country, and I honestly think any time of year is fine for your trip. On the other hand depends on what you want to do on your vacation. The popular time of year is late spring through early fall, meaning November - March period. Weather is great for all outdoor activities. If you are up to Southern Hemisphere skiing then pick Jun, July and August.