You can't do more than 6 days consecutively, and you must have at least 3 off in every 14. That's the basic rule. But there are no "school holiday" type leave periods, apart from a break over Christmas and New Year. You can request leave, but you have to specify why you want it and it's not automatically granted.
There is time to get back over Christmas if you so wish - a few of us did - but bear in mind it's the height of summer in NZ at that time, and many people use it to go and see a bit more of the rest of NZ, which you won't have a great deal of time to do otherwise.