https://www.transfermarkt.com/-what-day-of-the-week-are-frontier-flights-cheapest-/thread/forum/696/thread_id/27643/page/1#anchor_28332
https://www.transfermarkt.com/-what-day-of-the-week-are-frontier-flights-cheapest-/thread/forum/696/thread_id/27643/page/1#anchor_28332