Global – October 21, 2026 -- The NRF 4-5-4 Calendar adds a 53rd week to the retail reporting year roughly every five to six years, most recently in 2023, to keep sales comparisons aligned between years.
Calendar splits the year into 4-5-4 week months to match weekends and holidays
The voluntary industry guide divides the year into months of 4, 5 and 4 weeks. Comparable months contain the same number of Saturdays and Sundays, so like days are compared with like days in sales reporting. The layout also lines up holidays.
The format dates to an informal inter-industry discussion in the 1930s. Retailers had reported on a straight calendar, but weekends made up a growing share of sales while the number of weekends per month varied from year to year. Many stores adopted the 4-5-4 Calendar in the 1940s.
Extra day in a 364-day year forces a 53rd week in 2006, 2012, 2017 and 2023
Fifty-two weeks of seven days total 364 days, which leaves one day unaccounted for each year. Together with Leap Year, this makes a 53rd week necessary at the end of the calendar for sales reporting purposes only.
NRF adds the week if four or more days of January remain after the 52nd week. In 2016, only three days remained (January 29-31), so no week was added. In 2017, four days remained, triggering the 53rd week.
Restated calendar shifts 2017 weeks back by one to align holidays
To compare a 53-week year with the following year, the NRF calendar pushes each week of the 53-week year back one week and ignores the first week of that fiscal year. In the 2017 example, the first sales week runs February 5-11, 2017, rather than January 29-February 4 on the non-restated calendar. Holidays, which drive a significant share of retail sales, line up as a result. Retailers can instead leave the year unrestated and ignore the 53rd week of sales.
Sales release timing moves earlier in the week
The calendar also sets sales release dates, historically the first Thursday after month-end. As information flows faster, more companies now publish sales data earlier in the week.