https://central.xero.com/s/question/0D58V00009Pim0rSAB/aa-what-is-the-%F0%9D%97%B0%F0%9D%97%B5%F0%9D%97%B2%F0%9D%97%AE%F0%9D%97%BD%F0%9D%97%B2%F0%9D%98%80%F0%9D%98%81-day-to-book-flights-on-%F0%9D%94%B8merican-%F0%9D%94%B8%F0%9D%95%9Arlines