Microsoft will begin rolling out Windows 8.1 in mid-October.
The first major update to Windows 8 will arrive in New Zealand at 12am local time on 18 October.
"Windows 8.1 will begin rolling out worldwide as a free update for consumers on Windows 8 through the Windows Store," Microsoft said in a blog post. "Windows 8.1 will also be available at retail and on new devices starting on October 18th by market."
Microsoft released a preview version of Windows 8.1 at its Build developer conference earlier this year. It will be available to manufacturers by late August, allowing OEMs to pre-load Windows 8.1 on devices that will be released ahead of the holiday season.
Redmond stressed that PC buyers don't need to wait until October to pick up a new machine. "If you buy a Windows 8 device today, you can look forward to the new features and improvements from Windows 8.1 in October," the company said.
The announcement comes shortly after a "near-final" build of Windows 8.1 leaked online.
That included an array of new navigation tips and tutorials apparently designed to help users who had trouble with the sweeping interface overhaul in the first edition of Windows 8, which was released on 26 October of last year.