Skyscanner says 40 days for every route

Does Skyscanner tell you when to book a flight?

Yes, and it gives the same answer everywhere. Each Skyscanner destination page carries an FAQ headed with the words "When is the best time to book flights to" followed by the city, and the answer reads that the cheapest time to book a flight to that city is around 40 days in advance. On 16 September 2026 we read that line, unchanged apart from the city name, on the pages for Tokyo, New York, London, Dallas, Salt Lake City, Santo Domingo, Cancun, Los Angeles and Great Falls, Montana, and on the London to New York route page.

We then opened four more pages we had not planned to check, for Sydney, Bangkok, Paris and Dubai, and re-read the route page in a fresh session. Same 40 days. Fourteen pages, one number.

The same FAQ block has a second field, the cheapest month to fly. That one does change from page to page, which is what makes the fixed 40 stand out.

Why does Skyscanner show the same booking window for every route?

The FAQ answer opens by saying Skyscanner crunched all the numbers in its flight calendar. Read alone, on one page, that sounds like a calculation done for that destination. Read across fourteen pages it cannot be. Tokyo from the UK is a long-haul market served by a handful of full-service carriers. Great Falls is a small regional airport whose page showed a lowest return fare above six hundred pounds. Paris and Dubai are short and mid-haul markets full of low-cost seats. If a calculation had been run on each, the odds of every one landing on exactly 40 are close to zero.

The cheapest-month field proves the pages can hold per-destination values. Tokyo says December, London says October, Dubai says March. So the site is capable of printing a destination-specific answer in that block. It simply does not do so for the number of days.

The route page is the clearest tell. The London to New York page does not answer a question about London to New York. Its FAQ asks when to book flights to New York and answers with the destination sentence, 40 days. A route page that quotes a destination default has not looked at the route.

None of this says Skyscanner's fares are wrong. The live search on the same page is real. The point is narrower. The sentence that reads like a data finding is boilerplate, and a reader who plans around it is planning around a template. We cover the same pattern on other sites in one site, two answers on flight prices and Momondo still says 60 days.

How many days in advance should I book a flight, then?

There is no single number, and any page that gives you one without naming the route is guessing on your behalf. What actually moves the cheapest booking point is the route itself and the season you fly in.

Long-haul routes to a fixed-demand destination, Tokyo in cherry blossom season or New York over Thanksgiving, sell down their cheap fare buckets early, and the cheapest booking point sits further out. Short-haul routes dense with low-cost carriers open later and hold cheap seats longer, because those airlines price on load factor, not on a calendar. A regional airport with two or three daily flights behaves differently again, since there is little competition to push fares down at any point.

The other variable is who is telling you. Aggregators each publish a house figure, sometimes years old, sometimes with a hard limit on how far ahead they can even see. We track those separately in Kayak never looks past 183 days, Expedia moved its cheapest booking day and the 21-day rule is really 14 days. Read those before you treat any one number as the answer.

For Tokyo specifically, where the 40-day line is the most visible, we compare the windows that different sources publish for the same city in Tokyo booking window, 40, 87 or 175 days. The spread between them is the whole story.

What should you do instead of trusting the 40-day line?

Use the parts of the page that are computed for your route, and ignore the part that is not. In order of usefulness on the day we checked, this is what worked.

• Open the flexible-dates calendar on your actual origin and destination. Skyscanner's own page invites you to find the cheapest month or even day of the year to fly. That view is drawn from cached searches on the route, which is far closer to a real signal than the fixed FAQ line.
• Read the cheapest-month field, not the days field. It varies by destination, so it is at least being set per page. Treat it as a hint about seasonality, not a promise.
• Check the footnote before you quote a fare. Every page we read ends with a line saying prices shown are estimated lowest prices only, found in the last 12 days. The deals block is a snapshot of what other people searched, not a live quote.
• Set a price alert on the route and let the data come to you. The page itself recommends this. It is the one feature that watches your route rather than a template.
• Cross-check the airline's own site once you have a date. For long-haul and for anything over a holiday, the carrier's calendar view often shows the fare-bucket steps that an aggregator's lowest-price cache smooths over.
• Do not leave it to the last week unless the route is a busy short-haul. That part of Skyscanner's advice is sound in general even if the 40 is not.

How did we check Skyscanner's booking window?

We read the fourteen pages listed above on 16 September 2026 from a plain browser session with no account and no cookies accepted. The brief for this post named skyscanner.com addresses. From our location those addresses redirected to Skyscanner's Italian-language edition, so we read the English (UK) edition at skyscanner.net, where the FAQ text is printed in full. The sentence and the number are Skyscanner's, quoted as displayed. We did not infer anything from source code or from search results, and we did not run Skyscanner's own search for these routes. What the live search returns is a separate question from what the FAQ claims.

Our general rules for this kind of check, including why we only publish what we read on the day and why we name the exact page, are on the methodology page. Every figure on this site follows them, whether it is a fare, a fee or an eSIM price such as the ones in our Japan eSIM guide and Thailand eSIM guide.

If Skyscanner changes the FAQ text so that the number varies by destination, this page will be updated with the new readings and the date. Until then, take the 40 for what it is, a default.