https://central.xero.com/s/question/0D58V00009PjRFlSAN/what-days-are-flights-%F0%9D%95%94%F0%9D%95%99%F0%9D%95%96%F0%9D%95%92%F0%9D%95%A1%F0%9D%95%96%F0%9D%95%A4%F0%9D%95%A5-day-to-buy-tickets-on-%F0%9D%94%BC%F0%9D%95%A9%F0%9D%95%A1%F0%9D%95%96-booking