Absent an employment agreement, etc. to the contrary, as an "at will" employee you are under no obligation to provide notice when leaving your job. You should be paid for all time that you worked, even if you left with no notice.That having been said, if the gentleman is not physically or mentally independent enough to be left alone and leaving him with no back-up caregiver will put his life in jepoardy, you can face charges for elder abuse and worse. So just nake sure that is not the case.