In the lead-up to December 25, things like Christmas cake ingredients and Advent calendars will start to appear on shelves.
Fresh products like berries, ham, and items for the Christmas BBQ start to appear in the weeks before the big day.
"It's definitely been a really tough year for both our team and customers so we know some Christmas cheer and spirit won't go astray," Countdown's chief Christmas elf said.
"We know our team is looking forward to the fun of Christmas festivities a bit later down the track, and likewise our customers tend to get into the Christmas spirit earlier than December."
Elsewhere, at New World, Pak'nSave and Fresh Choice, customers will start to see Christmas stock appear from next month.
"With 2020 being a tough year for New Zealand, the thought of Santa and Christmas is something many of us are already looking forward to," Foodstuffs' head of corporate affairs, Antoinette Laird, said.
"So for the festive lovers amongst us, it'll soon be time to start thinking about what we'll be baking, making and treating ourselves with this year."