Twenty-four hours, and the clock does not reset.

Reload the page and watch the timer — If it jumps back up to a round number, it is counting from YOUR arrival rather than to a deadline. Ours will lose the seconds it took you to reload, because that time actually passed
Open it again in a private window — A per-visitor timer usually restarts for a browser it does not recognise. A real deadline does not care which window you are in
Come back tomorrow and try the code — The honest test, and the slowest. If a code still works a day after its countdown hit zero, the deadline was decoration and every future one from that shop is too
Watch for the round number — A timer that says "ends in 1 hour 59 minutes" every single time you visit is a script with a fixed starting value. Real deadlines produce awkward numbers, because that is what time does
What ours does — Ends at a fixed moment on our clock. The code stops working at that moment rather than a hopeful hour later, and the page will say the sale ended rather than quietly showing you the timer again
If we ever fail one of these tests — Tell us and we will honour the price you saw. That is what makes this section a commitment instead of a lecture about other shops

No "only 3 left" unless it is literally three — Most stock counters are a number chosen to be alarming. Ours are absent — if something is genuinely nearly gone the page says sold out when it is, which is the only version of that message worth trusting
No "twelve people are viewing this" — Nobody is counting. That widget is decoration with a plausible-sounding number in it, and it exists purely to make you decide faster than you meant to
No countdown that resets — Covered in full above, and it is the one we would most like you to test
No email an hour later saying we extended it — That message costs a shop nothing and costs everybody who hurried their trust. If the clock ends the sale, the sale is over
No secret discount for abandoning your basket — Waiting for that email is a rational response to a shop that sends it, which is why we do not — it would punish everybody who simply bought at the price
No fake sold-out badge to make the rest look scarce — It is the oldest trick on this list and the easiest to catch, because the item comes back the following week at the same price

There are four of these a year — Roughly one a quarter. You have not missed your only chance, and a shop implying otherwise is telling you about its marketing calendar rather than about the price
The list is told the day before — That is the entire advantage of being on it. Not a deeper discount, not a secret code — twenty-four hours of notice, which is genuinely useful and is all we are offering
This is not the lowest price of the year — Clearance goes deeper, on the stock that reaches it. If price is what matters most and the specific item does not, wait for that instead
Wanting it tomorrow is a better reason than the clock — If the thing is right, twenty-five per cent is a bonus. If it is not, twenty-five per cent off something you do not want is the most expensive kind of saving
Nothing here is going up in price afterwards — It returns to what it was. A sale ending is not a price rise and we will not describe it as one