Regular shoppers notice that the same items go on offer at intervals that feel familiar. That impression is accurate, because promotional calendars are built as repeating cycles.
The calendar is planned quarters ahead
Grocery promotions are scheduled well in advance so that supply, advertising and store execution line up. Each week's featured items are chosen long before the week arrives.
Within a category, brands rotate through the feature slots so that something in the category is always promoted and no brand is promoted continuously.
The rotation length depends on how often households buy the product, which is why staples cycle faster than occasional purchases.
Suppliers fund the feature
Promotional pricing in grocery is typically supported by the manufacturer through trade funds negotiated for a defined period.
Those agreements come with expected volume, display placement and advertising, which is why a promoted item appears in the circular and on an end display simultaneously.
Because funding is committed in blocks, the promotion runs for its agreed window rather than until stock clears.
Pantry loading is the intended effect
The purpose of a repeating promotion is to get households to buy more than one unit and store the surplus. A stocked pantry blocks a competitor's promotion the following week.
That is why cycle length and typical consumption rate are matched. The offer returns at roughly the point a household would run out.
It also explains multi-buy structures, which push the purchase quantity past what a single-price discount would achieve.
The regular price is part of the design
A promotional price only reads as a saving against a reference price, so the non-promoted weeks are doing work even when nobody buys.
Items promoted very frequently develop a shopper expectation that the promotional price is the real one, which erodes the reference and eventually forces a reset.
Retailers manage that by varying the depth and format of the offer rather than repeating an identical discount indefinitely.
Using the cycle without tracking it formally
A household that notices which items in its own basket recur on offer learns the rhythm for the products it actually buys, which is a much shorter list than the whole store.
Buying the cycle rather than the week means purchasing enough at the promoted price to reach the next appearance, limited by storage and by shelf life.
Where an item never seems to cycle, it is usually either an everyday-low-price line or one without supplier promotional support, and waiting will not help.