Changing Date Format

Hi there,
I’m in NZ so I’d like to change the default date format to dd/mm/yyyy. I’ve tried date-format:dd/mm/yyyy, date-format:dd/mm/yy, date-format:dd-mm-yyyy and I’ve looked at older posts about this issue but they’re a few years old and none of the suggestions have worked.

What’s the proper way to do this?

Cheers.

https://ww.wp.xz.cn/plugins/contact-form-7/