For example:Â Airplane Tickets
When to buy: On a Wednesday, 21 days (or a couple of days earlier) before your flight.
Why: Airlines make major pricing changes (and run fare sales) every week, typically on Tuesday evenings and Wednesday mornings. About 21 days out from your flight, you’ll see plenty of deals out there as airlines scramble to fill seats. Don’t wait much longer, she cautions; prices jump significantly from 14 to seven days ahead of departure.