|While it is excellent that you are a punctual person, being punctual actually means arriving at the exact appointed time; it does not mean arriving early. While it is never a good idea to show up late for a job interview, it is not a good idea to show up very early either.|
While you are correct in stating that arriving 30 minutes early can indicate that you are enthusiastic and eager, it can also send some less appealing messages. For example, it can indicate that you are rather desperate, needy, or dependent. It can also indicate that you do not have much to do. And worse, showing up this early can lead an interviewer to infer that you do not have much respect for his or her time.
When you arrive this early, most interviewers are going to wonder why in the world you have done so, and they can easily regard your arrival as an interruption.
As a result, you should listen to your friends on this one. Ideally, you should arrive for a job interview around ten minutes early. Anything earlier can raise questions in an interviewer’s mind, and you want the interviewer to be unquestionably impressed with you.