The New Day is edited by Alison Phillips, the Mirror's weekend editor.
At the time of its launch, the group said the title would cover news and features in "an upbeat, optimistic approach and will be politically neutral".
Trinity, which also owns the Daily Mirror and a host of regional titles, said The New Day would initially be available free of charge from 40,000 retailers, before trialling at 25p for two weeks and then selling for 50p after that.