"Optimisation means you take a look at market demand and how many flights you've got and you change your schedule accordingly - all airlines do it."
He said the airline would not cancel flights for commercial reasons in less than a seven-day period.
"You don't do that because it stuffs everybody up but looking further out decisions are made ensuring the majority can be put on to other flights within a matter of hours."
While around 300 services had been dropped over the two months, the spokesman said there were 2600 domestic flights over that period.
Most of the cancellations were on the Auckland-Wellington route where it has most of its services.
"It has to be taken in context - we put 600,000 new seats into the market last year which is a big increase."
The airline - which is investigating flying regional routes - also flies transtasman services.