The .nz Registry reactivates domain names on the hour, every hour. If you have just renewed your domain name the .nz registry will reactivate it on the next hour and all services will resume. It also depends on how long the domain has been expired. If the domain has been expired for over a couple of days, then yes it will take a little longer for services to resume. If it has just expired, then the services will come back on line quicker.