Way too late and likely you are running into school holidays.

With NZ business class awards best to check no later than 9-11 months out (11 months for Dec-Feb period, perhaps 9 months for rest of year). While awards may be found closer to departure (eg pax release awards they've held, or NZ decides bookings low enough to warrant some extra award seats) it is not predictable enough to count on this.

If you have specific dates in mind check you can get a clue from looking at availability tools for the paid fare classes. NZ has C D J and Z. If no J or Z then most unlikely any more awards will be released (except maybe a few days before departure). If they are all showing 4s then keep checking (especially if UEO premium economy booking classes also have availability).

Usual thing to avoid school holidays, avoid Fri through Mon (peak business travel dates), etc.

NZ key dates - school holidays are 5-20 July 2008.