https://intercom.help/expedia-436c84/en/articles/11175165-how-can-i-change-the-date-on-my-united-airlines-ticket
https://intercom.help/expedia-436c84/en/articles/11175162-official_ua-oops-change-passenger-date-on-united-business-class-ticket
https://intercom.help/expedia-436c84/en/articles/11175156-no-waiting-how-to-change-passenger-date-on-united-business-class-ticket
https://intercom.help/expedia-436c84/en/articles/11175128-no-wait-on-date-change-change-passenger-date-on-american-business-class-ticket
https://intercom.help/kaju-pandey/en/articles/11175126-american-airlines-date-change-policy-a-guide-to-know
https://intercom.help/kaju-pandey/en/articles/11175125-how-do-i-change-passenger-date-on-american-flight-reservation
https://www.badgerandblade.com/forum/threads/10-ways-to-connect-with-american-airlines-customer-service.669056/