https://central.xero.com/s/question/0D58V00009NuX6gSAF/what-is-the-cheapest-day-to-book-a-flight-on-delta-customersupport247
https://central.xero.com/s/question/0D58V00009NuX6gSAF/what-is-the-cheapest-day-to-book-a-flight-on-delta-customersupport247
https://central.xero.com/s/question/0D58V00009NuX6gSAF/what-is-the-cheapest-day-to-book-a-flight-on-delta-customersupport247