https://www.sterlingfoundation.org/forum-1/general-discussion/what-is-the-day-to-book-flights-onhttps://www.sterlingfoundation.org/forum-1/general-discussion/what-is-the-day-to-book-flights-onhttps://www.sterlingfoundation.org/forum-1/general-discussion/what-is-the-day-to-book-flights-on