To dream that you are missing something, denotes a sense of being out of control and being disorganized.
Missing an event or time frame—such as missing an exam, appointment, bus, scheduled payment—can represent a missed opportunity or neglected responsibility, or a fear of one of these. Consider also the reasons why you were late in the dream. For example, if it's because you forgot to set the alarm or you forgot to check your to-do list, perhaps you're feeling overwhelmed or disorganized in your real life.