For the first time in decades, the Broadcasting Standards Authority (BSA) is making changes to the way it classifies TV programmes.
In May, the old PGR and AO tags will be replaced with M, 16 and 18 classifications.
M-rated shows will soon be allowed to play from 7:30pm, while PG content can run all day.
BSA chief executive Belinda Moffat says it could be good news for parents.
"This will enable some scheduling of children's movies at a time that will enable kids to watch it a bit earlier," she told Newshub.
"It also means that they can go to bed a bit earlier too."
She said it's the right time for changes as viewer habits are evolving. There is, however, an expectation that broadcasters will act responsibly.
The BSA will launch a new website to provide viewers with information about the changes.
Moffatt said the BSA encourages parents and caregivers to also use parental lock or control features, which are available on both Freeview and Sky.
"We also encourage audiences to read the classification and programme information that is provided by broadcasters to enable viewers to protect their families from content that may harm.
"These are important safeguards provided through the broadcasting standards system and are there to help viewers inform themselves about the viewing choices they make."