Can a juror REALLY be excused to go on vacation?Am I missing something?

I am referring to the trial of the ex-BART cop for murder. The shooting occurred in the Bay Area but the trial is being held in LA now. The news reported that a juror is being excused "because of vacation." I thought that one had to have an illness, a sick relative or something serious to be excused during jury deliberations. What gives? Doesn't the judge warn jurors that the trial and deliberations may take a long time and that ppl who don't have the time should speak up BEFORE the start of the trial?