When to book a domestic flight (and when waiting pays)

There's no single magic booking day, whatever the internet says. But there are patterns, and knowing them stops you buying too early or waiting too long.

The broad window

For flights within the US, fares on most routes sit lowest somewhere between three weeks and three months before departure. Earlier than that, airlines often haven't released their cheapest fare buckets. Later, the cheap seats have sold and prices climb toward the fares that business travelers pay.

Peak dates change the rules

Thanksgiving, the December holidays, spring break and long summer weekends behave differently. Demand is so predictable that low fares disappear early. For those dates, book as soon as your plans are fixed, even if that's four or five months ahead.

Which days to fly

The day you fly matters more than the day you book. Tuesdays, Wednesdays and Saturdays are often cheaper than Fridays and Sundays because fewer commuters and weekend travelers want them. If your dates can shift by a day, ask us to price both.

When waiting can work

• Routes with many competing airlines, where a fare sale can appear at short notice.
• Off-peak midweek trips outside school holidays.
• Trips you'd happily skip if the price never drops.

Use the 24-hour window

Under US Department of Transportation rules, tickets for flights to, from or within the US, booked at least seven days before departure, can usually be held or cancelled without penalty within 24 hours. If you're torn, booking and reviewing the next morning is a sensible middle path. We'll tell you whether your fare qualifies.