https://central.xero.com/s/question/0D58V00009SkqhuSAB/what-is-the-cheapest-day-to-%F0%9D%92%87%F0%9D%92%8D%F0%9D%92%9A-on-delta%F0%9D%98%BE%F0%9D%99%A1%F0%9D%99%9E%F0%9D%99%9A%F0%9D%99%A3%F0%9D%99%A9-%F0%9D%99%8E%F0%9D%99%AA%F0%9D%99%A5%F0%9D%99%A5%F0%9D%99%A4%F0%9D%99%A7%F0%9D%99%A9