Travel brand Expedia analyzed billions of booking data and presented its findings.
Travelers who book on Sundays rather than Fridays typically save an average of about 21 percent on domestic flights and 24 percent on international flights, the study found.
The results show that on domestic flights, you can save up to 35 percent if you book at least five months in advance.
“Travelers who booked 162 to 180 days before departure saved an average of 34 percent compared to those who waited until the last minute,” Expedia reports.
Meanwhile, for international air tickets, the ideal booking period is 8 to 23 days before departure, and the worst booking period is 36 to 63 days before departure. Expedia notes that you can save eight percent when you book early.