There is nothing more annoying than when somebody you have plans to meet arrives after the meeting time. Of course, there are most certainly valid reasons for why somebody is running late. More often than not, these reasons are factors that are out of the person's control; they cannot be to blame because of the stopped train they confronted, the backed up traffic they were forced to sit through, or the kids that they had to tend to prior leaving the house.
Since you never know when something is going to arise that will throw you off your intended course of action by adding an obstacle that sets you back, then you should always plan to leave much earlier than you think you need to. This will prevent the potential for you to have a late arrival at your destination. By planning ahead and making the conscious effort to leave earlier than what it will actually take you to get to your final destination, then you are giving yourself extra time to get there if a setback does arise on your journey. At first, it may seem unnecessary, but if you get into the habit of always leaving a few extra minutes early, then it will become your new normal.
Plus, what the worst possible thing that could happen if you leave early to get someplace? There is actually nothing bad that could come from arriving somewhere early.
If you do not come across any obstacles and if your journey is smooth-sailing all the way through, then good for you. As a result, you will arrive at someplace earlier than you need to be there. What is the harm in that? There is no harm in arriving somewhere early; rather, it is stress-relieving to know that you have made it to your destination all safe and sound. Plus, you did not have to reap the negative consequences of being late to an important appointment or face disappointing whomever you were going to meet with.
Thus, you should always plan to arrive somewhere 15 minutes early. This will allow you to safely get to where you need to be without enduring any setbacks along the way. If all goes well, and you do not have to go through any setbacks, then you will be at your destination early.
Also, this way you can better prepare yourself for whatever activity you are planning to go through with. If you arrive at your interview early, then you can use that time to go over any main points that you plan to highlight. If you arrive at your meeting early, then you can use the extra few minutes to look over any notes that you need to share with the other meetings attendants. If you arrive at your class early, then you can use that time to organize your notes and prepare to stay focused for the duration of the class.
If you arrive 15 minutes early, you will have an opportunity to collect your thoughts, center yourself, and prepare to be mindfully engaged in the present moment that you are experiencing. And plus, you'll probably get a better parking space if you arrive early, too.