https://intercom.help/airlines-support-aefaa9296861/en/articles/10802804-discount-den-what-is-the-cheapest-day-to-buy-air-france-tickets
https://intercom.help/airlines-support-aefaa9296861/en/articles/10802804-discount-den-what-is-the-cheapest-day-to-buy-air-france-tickets