"We're making some adjustments to our regional schedule to better align our flights to when our customers want to fly," he said.
"Jetstar's regional network has been a success story for New Zealand travellers, bringing low fares to areas that had previously lacked competition and choice."
Under the current flight schedule, Jetstar operates early morning flights between 6am and 8am out of New Plymouth, Nelson, Napier and Palmerston North.
However under the incoming schedule, the earliest flight out of New Plymouth would be 11.45am.
Napier would also lose its early morning flight to Auckland with customers set to arrive there at 10am instead of the current 7.35am.
Nelson's 6.30am flight to Auckland would also be changed to depart at 10.15am with Palmerston North's first flight also pushed out.
The spokesman said the earlier flights had been shifted to later in the day, however the airline was putting on earlier flights out of Auckland for business people travelling to the regions.
"New Plymouth is more a leisure market for us so we have the mid-morning and mid-afternoon flights all week with the extra two weekend return services, on Friday and Sunday evenings," he said.
"These services are targeted at weekend travellers coming to New Plymouth or locals heading to Auckland."
This time last year Jetstar operated 122 return flights a week on the regional routes.
That was reduced in July this year to the current seasonal schedule of 104 return flights.
Hawke's Bay Chamber of Commerce chief executive Wayne Walford said he hoped this wouldn't impact on business travellers too much, but said Jetstar may be looking to fill a gap in the market at that time.
"There are a lot of people that fly in and fly out early in the morning - I'm not sure what the numbers are but it is very busy. There's certainly a lot flying out of here," he said.
"They may be trying to avoid competing directly with Air New Zealand because you see Jetstar and Air New Zealand in at the same time and going out within five minutes of each other so that direct competition may not have paid off for them."
Air New Zealand operates early morning flights to and from Nelson, Napier, New Plymouth and Palmerston North during the week.