Constantly running late is not an excusable behavior. Constantly running late is your choice for which you alone are responsible. So what can you do?
First, accept your personal responsibility for your problem.
Next, break the problem down into specific behaviors such as sleeping too late, finishing one more thing, underestimating travel time, misplacing essential items, disorganization in your house, meetings that run longer than planned, affecting others negatively and postponing destinations and tasks you dread.
Psychologists say that if you face the same issue repeatedly, there’s probably an identifiable problem — and once you identify it, you can develop strategies to solve it. Being late is just such a problem. Therapy can help, but so can discipline and being honest with yourself about your behavior.
Life is in the details. Pick one problem and change your behavior. Go to bed earlier and don’t call it sleep. Call it rest. If you lay quietly in the dark, your body from the neck down does not know the difference between sleep and rest. Organize your house. Hold yourself accountable to maintain the organization, and hold others accountable to maintain your organization and their own organization. If you are running a meeting, set a timer where everyone can see it. The motion to adjourn has already been seconded and passed when the timer rings. Consider others. Would you hire someone who is chronically late? Would you invite someone to be on your committee if you knew they were chronically late? Why are you choosing to act this way?
To learn more about the common reasons for being late, read Gretchen Rubin’s article, Chronically Late? 8 reasons for Being Late & How to Beat Them from the World of Psychology.