It shows that the least expensive air tickets were purchased on Sunday for both domestic and international flights. Monday through Friday, tickets bought on Tuesday were the lowest.
The Airlines Reporting Corp. researched airline ticket purchased January 2013 through July 2014. Nearly 130 million tickets worth $94 billion purchased in the U.S. were included in the study.
It also found that the least expensive airfares were purchased eight weeks in advance for U.S. domestic routes and 24 weeks in advance for international destinations.