What are the top reasons a judge will grant a continuance and postpone a trial when trial is 1 week away?

There could be a million reasons why a judge may find good cause to adjourn a trial that is a week away. It is difficult to provide a "top ten list" of reasons, but most often trials are adjourned if there is a evidentiary issue or discovery issued raised by an attorney, an issue with a witnesses in a particular case, or even if the defense or prosecuting attorney needs more time to prepare for trial (although preparation is usually not a sole reason for a judge to grant a continuance).