Originally Posted by
Nightowl888
The ability to change to another flight free of charge on a flexichange/flexirefund ticket on the same day opens midnight NZ time, not T-24 as some are lead to believe.
I’ve waited til 12:01am several times and changed my flights in the app. It’s a super easy process, it just brings up the usual flight change option but all flights on the same day for the same routing are “change from $0”. Hope that helps

Perfect handle for this advice! I have done this many times.
I have in a couple of cases where bookings are very heavy, paid for a FlexiRefund on the preferred flight just to cover that flight being completely sold and being unable to move my cheaper FlexiTime/Refund. If the target flight is fully sold, then just after midnight I cancel and release 1 seat, which I then acquire with the free change from the other Flexi. Of course, you have to allow AirNZ to hold up to $450-ish for a few days until the refund shows. But this has worked well over a couple of Christmas periods.