Assistance League Professional Humanitarian Auxiliary's primary fundraising event is the Day of Authors. It has been held in March every year for the last 17 years. The event is held at California State University, Fullerton. This full-day event features prominent authors, book signings, book sales, opportunity basket drawings and lunch. Each year, the event's 550 seats immediately sell out. Funds raised from this event help implement ALPHA'S philanthropic projects. The members spend a majority of the time they devote to their auxiliary, in the planning and organization of this event. Each member is responsible for contacting corporate donors, providing objects for and the building of the opportunity baskets, inviting guests and participating in the day's organization. Assistance League Professional Humanitarian Auxiliary is assisted in this venture by the Amerige Heights Barnes and Noble Bookstore who staff and supply all the books to be sold during the event. In turn, a generous percentage of the book sales is donated to Assistance League Professional Humanitarian Auxiliary for funding their philanthropic projects.

Some of the notable authors who have been keynote speakers are A. Scott Berg, Pulitzer Prize winning author of Lindbergh and Kate, a biography of Katherine Hepburn. Last year, Doris Kearns Goodwin, also a Pulitzer Prize winning author and presidential historian, was the keynote speaker. All of the authors spend a great amount of time signing books for those attending the event.