It seems that some people do not understand that there are two events that commemorate the Gettysburg Address.
DEDICATION DAY is always held on November 19 (regardless of day of the week), the anniversary of the dedication of the National Cemetery in 1863. The lead sponsor of the event is the Lincoln Fellowship of Pennsylvania, the GNMP, Gettysburg Foundation and Gettysburg College assisting. The main event is a speaker in the cemetery. Last year it was Steven Spielberg. For the 125th in 1988 it was Chief Justice William Rehnquist and for the 100th in 1963 in was Pennsylvania Governor William Scranton. For a complete list of speakers see http://www.lincolnfellowship.org/dow...20speakers.htm. Presidents have been invited in the past but none have attanded.
REMEMBRANCE DAY is held on a Saturday close to November 19. It is sponsored by the Sons of Union Veterans of the Civil War and includes a parade, wreath laying ceremony at the GAR Woolson Monument, and Civil War Ball. The date change this year had nothing to do with the invitation to the President to attend Dedication Day.
As a member of the Lincoln Fellowship and the Sons of Union Veterans who has attended many of these events in the past 49 years, I hope this provides some clarification.