Want to see all the New Zealand public holidays on your calendar on your Google Calendar, but don't want to have to enter them yourself, or maintain them?
I found this great page with public holidays and calendars on the MBIE site. They have the New Zealand public holidays here for the current, past and future years for your reference. They also have this great link to an icalendar (ics) url for National public holiday dates, including all regional anniversaries (linked here for your reference) on the NZ public holiday iCalendar feeds page.
I've been using this with my personal and work Google calendars, but it should work for you anywhere *.ics web calendars are. Just right click the ical link, and select 'Copy link address' (or equivalent in your browser of choice). Then in Google Calendar, click the arrow on the left hand side beside 'Other Calendars' and select 'Add by URL'. paste in the url, click 'Add Calendar' and your done.
*[MBIE]: Ministry of Business, Innovation and Employment