We published the ACCU 2019 schedule a month ago. There is the usual disclaimer that the schedule is subject to change without notice till the end of the conference – at which point the schedule is a record of the history so no further changes are possible. This usually means just amendments to the sessions, quickies, side events, or social events, as the keynotes are normally fixed points.
This year an unusual situation means we need to swap two of the keynotes: Herb’s Saturday closing keynote has become Thursday’s opening keynote; and Kate’s Thursday opening keynote has become Saturday’s closing keynote. Given the circumstances this year, this was unfortunately The Right Thing To Do™ even though it is a change to the keynotes post publication of the schedule.