I had a thought to cutover to Flick electric and run a timer on the Hot water cylinder to make use of night rate.. as per comments here:

http://news.flickelectric.co.nz/2015/11/26/how-to-save-more-with-flick/

I called flick and gave them my address (Auckland, North Shore) and they said it wasn't available.

What determines if night rate is or is not available for a given premise?
Would calling other retailers make ant difference? or is this something controlled by the lines companies?

Cheers