Plane tickets usually don’t get cheaper closer to the departure date. Flights tend to be the most inexpensive when you book between four months and three weeks before your departure date. According to the CheapAir.com 2019 Annual Airfare Study, you can expect rates to go up after that period.
For U.S. domestic flights, the cheapest days to fly are usually Tuesdays, Wednesdays and Saturdays. For flights to Europe, weekdays tend to be cheaper than weekends. These examples show round-trip fares for travel in June (found this week on my fare comparison site).Mar 2, 2017