That's not how time limited actions work.
In most of Europe at least there are strict laws on pricing so if you make a discount, it can't just time out after 10 minutes, it needs to last the end of the business day or until the stock is depleted.
These stric pricing regulations is probably why electronic shelf labels were invented in Europe, to make sure there will be no discrepancy between the price on the shelf/discount and the price on the register, otherwise the store is liable.