A bad day is a term used to describe an unpleasant or difficult situation, experience or occurrence that causes discomfort, frustration, disappointment or sadness. It can refer to any event or series of events that goes wrong, resulting in negative emotions and feelings of unhappiness. A person may have a bad day at work, school, home or even while out in public. The cause could be anything from an argument with someone, receiving bad news, experiencing failure or loss, feeling sick or tired to encountering unexpected obstacles or challenges. In summary, a "bad day" is any day that does not go as planned and leaves one feeling unhappy or discontented.