I am a unpaid intern at a tech company and several weeks ago I had my first performance evaluation. While my manager told me that the code I had been submitting was excellent and that my work was more than solid, they noted that I had been leaving too early from work and that this called my dedication into question.

Now, our official start and ends times are from 9:30 to 6:00 so everyday for the past several weeks I have been working hard to finish my days tasks and then leaving at 6:00. When I asked why this was a problem the response I received was that I should always be looking for more work.

I really enjoy where I am working and I really want to leave a good impression with my manager however, as an unpaid intern, I don't think it's smart to burn myself out working 12-hour days, especially when I have been able to get my work done on time. I also have a number of responsibilities at home that make working late very difficult.

How should I best approach this situation with my manager? As I said, I took the feedback very seriously and want to show that I am a dedicated part of the team.