3rd time is too much I think. If this is really an outage again for the same people that suffered last week and the 1st time around then they are not going to forgive TCNZ this time. I see VF gaining more users now.
If Telecom needs to do any work on the network to address any of the issues from the recent outages then they will obviously need to carry out maintenance work,
Generally doing it after midnight is the norm, possibly doing it first thing after midnight so if any issues they do have time to start addressing any unforeseen problems as they are probably a little bit gunshy right now.