For tv purposes it is 5pm (aus)
Sunday 7pm is quite a good time to be watching a game on tv. I'm sure many people will prefer that option rather than attending.
I think that's a big problem with NZ sports fans in general. If you have a 60 inch LCD in a living room big enough to host a few people, why wouldn't you stay at home and drink cheap/better beer, eat cheap/better food with good company when you know what you get at the stadium - ie an average atmosphere, shit quality food, at times shit weather and then there's the ticket/parking prices. Regardless of when it is I think a lot of people are preferring to stay at home because you get better value.
Also you don't have to worry about the kids potentially losing interest because they can find something else to do.
But yes in this case, all the more reason to stay at home - maybe even for some more usually keen fans.