Staying in Australia for a day on transit visa and returning to New Zealand

There is nothing such as a Transit (in terms of Immigration) if your Origin and Destination are same, so you can't use that visa for this itinerary.

To add some official sources into the mix

You might be able to get a Transit visa (subclass 771) if you:

• need to pass through Australia on your way to another country or
• need to pass through Australia to join a ship as a member of the crew.

So you can not use a transit visa when you are not transiting Australia on your way to another country. However if you were flying to some other country like for example India from NZ you could stay up-to 72 hours in Australia during that transit.

Also, if its a single transit visa (which most of them are unless you are a ship crew member) It was issued on a given itinerary you provided in your application and hence it will be hard to convince the IO to even use it for a different transit than originally requested.

Here is what the application form requires, and I am sure you have submitted this information.

You must enclose with your application:

• a passport valid for travel to Australia issued to, or including, each person in the application;

• a recent passport-type photograph of each person included in the application (the photograph must be signed on the back by the person to whom it refers);

• an itinerary;

• evidence of confirmed onward booking to continue your journey from Australia to a third country within 72 hours of arrival;

• and correct documentation (eg.visa) for entry to that third country.

(The emphasis is mine)

This itinerary does not have any third country involved so the answer is a definite No.