Had correct codes for both. IRD calculators are up and operational on their website again. Using them shows a $600 refund
Are you talking about the generic (i.e. simple, non-detailed and not personalised) income tax calculator on their site?
Over the past few years IRD has had a personalised calculator where you could work out your tax situation in detail - but without committing yourself to a submitted return. You could enter all your income info (wage/salary, Super, pensions, interest, dividends etc - plus tax deducted at source like PAYE, Resident Withholding Tax etc) and get an exact calculation of your refund or payment due. The IRD said they would not be able to see the info you entered. However, if you wanted to use that info to submit an actual return later on, you could use the data you saved and submit it online.
This latter calculator does not seem to be there now. Maybe it's still coming or maybe they are not doing things that way this year. I had an email from them yesterday saying they would be in touch with me in a couple of months, setting out the info they have on me and I will need to correct/update it if necessary.