Your manners at the end of a double shift say more than your manners at the interview.

Politeness while you are rested and being assessed is performance, and everyone knows it, which is why it buys so little. The version of you at hour eleven with sore feet and one customer left is the version your coworkers plan around. That is who they mean when somebody asks what you are like to work with.

Take the last twenty minutes of your next long shift and run them like the first twenty. Thank whoever is closing with you and leave your station better than you found it. Being tired is a reason, and it is not a permission slip.