Four Jetstar flights between Wellington and Auckland were delayed because the airline forgot about daylight saving.
The 8.15am flight out of the capital on Sunday was about an hour late while crew waited for the plane to arrive from Cairns.
Clocks went forward early on Sunday morning, but that wasn't factored into schedules. As a knock-on effect, three later flights on the route were delayed.
One disgruntled Wellington passenger, who did not want to be named, said: "We only found out when we got on the plane. They said, 'The flight's been delayed because of daylight saving' - as if daylight saving was the problem."
It is understood schedules are configured by computer - but a further manual check was not made.
Jetstar provided a written statement from Australia.
"Our ground staff and cabin crew made sure passengers were aware of the delay and apologised for any inconvenience caused . . . The flight departed Cairns on time and was flying over the Tasman Sea when New Zealand's time-zone switched to daylight saving which meant the aircraft was late arriving into Auckland."
It added: "Once Australia changes to daylight saving this week, any anomalies for trans-Tasman services will be eliminated."
- Fairfax Media
Is New Zealand's airport security stringent enough?Related story: Risky objects bypass Wellington Airport security