"Weekdays between 3pm and 5pm and Saturday afternoons are the busiest times to shop," head of corporate affairs Antoinette Laird said.
"We see a peak in footfall on paydays, such as every other Wednesday or around the 15th of every month, as some shoppers budget their big shops around their paydays."
Between 9am and 10am was typically a slower time to shop but if shoppers could only make it during peak times there were advantages, Laird said. Busy times meant sample stands were more likely to be scattered throughout stores, giving away free nibbles and offerings to customers, so it wasn't all bad.
A spokesperson for Countdown said weekends were busiest and during the week lunchtime, after school and after work was also busy.
However, around three million customers walked through their stores each week, often more than once.
"It's no longer the norm to buy fruit and vegetables once a week and we find customers often visit every couple of days to buy their fresh produce or top-up key ingredients," the spokesperson said.
"Another part of the shift is the way we live now, we have an incredibly diverse culture and our houses have also changed a lot over time.
"We simply don't have the space or inclination we used to for storing food in chest freezers or pantries, which also drives that more regular shopping pattern."