DIRECT ANSWER
Walmart uses the NRF 4-5-4 retail calendar. Supplier weeks run Saturday through Friday, the fiscal year starts near the end of January, and WMYYWW labels the fiscal year and week number; for example, WM27W14 is fiscal 2027, week 14.
Walmart runs on the NRF 4-5-4 retail calendar. The fiscal year ends on a Friday within a few days of January 31 (usually the nearest one), and the next fiscal year begins the following Saturday, so fiscal 2027 (FY27) runs Saturday, January 31, 2026 through Friday, January 29, 2027. Weeks run Saturday through Friday and are numbered from the start of the fiscal year, written in the WMYYWW format: WM27W14 means fiscal year 2027, week 14. Nearly every supplier-facing surface (scorecards, reporting dashboards, and week-keyed reports) keeps time in these weeks, not calendar weeks.
What does the WMYYWW format mean?
WMYYWW breaks apart as WM, a two-digit fiscal year, then W and a two-digit week number. WM27W14 is week 14 of Walmart fiscal 2027, which runs Saturday, May 2 through Friday, May 8, 2026. The week count starts at W01 on the fiscal year’s opening Saturday and runs Saturday to Friday from there.
The trap sits in the year label. Because FY27 opens on January 31, 2026, almost all of fiscal 2027 happens during calendar 2026. A report stamped WM27 is not describing calendar 2027; it is describing the fiscal year that ends in early 2027. Scintilla’s numeric week code runs the other way: it numbers the year by its starting calendar year, so the same week reads 202614 there. Reconciling Walmart data against systems keyed to calendar months is where this bites; when the numbers refuse to tie, the year label is one of the first places to look.
When does Walmart’s fiscal year start and end?
The fiscal year ends on a Friday within a few days of January 31 (usually the nearest one), and the next fiscal year begins the Saturday after that Friday. FY27 runs January 31, 2026 through January 29, 2027; FY28 begins Saturday, January 30, 2027.
One nuance worth filing: Walmart Inc.’s corporate financial year, the one in the 10-K and earnings releases, ends exactly on January 31 every year. The Saturday-to-Friday week calendar described here is the merchandising and reporting structure suppliers actually work in, and its year-end floats a few days around January 31. The two share the FY label and end within days of each other, which is close enough to ignore day to day and just far enough apart to matter when reconciling supplier data against Walmart’s financial filings.
How do Walmart quarters map to calendar months?
Approximately: Q1 is February through April, Q2 is May through July, Q3 is August through October, and Q4 is November through January. The 4-5-4 in the name is the NRF’s fiscal-month pattern: a four-week month, a five-week month, then a four-week month, so each quarter is thirteen weeks (fourteen in the last quarter of a 53-week year).
The placement of Q4 is the point. It holds Thanksgiving, Christmas, and New Year in a single quarter, which makes it the largest selling quarter, and explains why pre-Q4 planning conversations with buyers typically happen in July, at the end of Q2, months before the season itself.
How do I convert a calendar date to a Walmart week by hand?
Find the Saturday that opened the fiscal year, count the days elapsed since it, divide by seven, and add one. Here is the full conversion for October 15, 2026:
- Place the date in a fiscal year. October 15, 2026 falls on or after January 31, 2026 and before January 30, 2027, so it belongs to FY27.
- Find the W01 anchor. FY27’s first week began Saturday, January 31, 2026.
- Count days elapsed. From January 31 to October 15, 2026 is 257 days.
- Divide by seven. 257 ÷ 7 = 36 remainder 5. Thirty-six full weeks have finished, so the date sits in week 37.
- Write it out. October 15, 2026 is WM27W37, the week running Saturday, October 10 through Friday, October 16, 2026.
The cross-check: the week’s opening Saturday should be the anchor plus 36 × 7 days, which lands on October 10, 2026, a Saturday, as it must be. A week that opens on any day other than Saturday means the anchor is off. The free Walmart week converter runs this same calculation in both directions: date to WM week, or WM week to its Saturday-to-Friday date range.
Why does “week 47” almost never mean calendar week 47?
In a Walmart context, an unqualified week number is read as a Walmart fiscal week. When a buyer says “let’s hit it by week 47,” they mean the WM week, and the gap from the calendar week of the same number is large: calendar week 47 of 2026 falls in mid-November, while WM27W47 runs December 19 through 25, 2026, which is Christmas week. The two readings sit roughly five weeks apart: the week before Thanksgiving versus Christmas week.
The ambiguity only appears where Walmart weeks meet calendar-keyed systems, and the full WMYYWW form removes it downstream.
What is a 53-week year and why does it matter?
The 4-5-4 calendar inserts a fifty-third week every five to six years to absorb calendar drift, and Walmart’s most recent one was FY24, which ran January 28, 2023 through February 2, 2024. The extra week lands at the end of the fiscal year, and the following year’s year-over-year comparisons carry a one-week offset unless the comparison is restated.
A related structural point: the calendar year-end always lands deep inside the fiscal year, never at the W01 boundary. December 31, 2024 fell in WM25W48, and calendar 2025 began mid-week inside that same WM25W48. Event weeks also move year to year even without an insert (Thanksgiving and Easter float), so a holiday’s week number is a property of that year’s W01 anchor, not of the holiday; last year’s number does not carry over.
What do you do with a WM week once you have it?
The conversion is the easy half; the converter handles it. The hard half is what a WM week implies mid-task: which scorecard week a late shipment counts against, which fiscal year’s OTIF invoicing schedule governs a deduction (Walmart publishes that schedule per fiscal year), whether the reset week a buyer quoted came from this year’s anchor or last year’s. Retail Reason answers those follow-up questions the same way this article was written: plainly, with a verification date and a confidence class on every answer. You can see how it checks a plan for calendar-shaped assumptions at the pitfalls check, or see pricing.