[MotherBear]

What Beth says is correct IF you want to qualify for your Indefinite Returning Resident's Visa. You need to stay about 6 months in NZ for each of the first 2 years after which time you can get the IRRV which allows you to come and go from NZ as you like and for as long as you like (within reason).

If you aren't too worried about getting the IRRV after 2 years, you can leave NZ for longer periods, but you must make sure to apply for a new RRV before the old one expires. I would guess that INZ would be monitoring your reasons for not being in NZ for such long periods and if the reasons weren't good enough they would see it as you not having sufficient commitment to NZ.

Something important to note: if you claimed points for an offer of skilled employment, you must take that job up within three months of being granted your permit. You must also stay in that job for at least three months and provide INZ with evidence that you have met these requirements within seven months of being granted your first residence permit.