Can my friend from the Philippines extend his visa if it expires tomorrow?

A friend from the Philippines is concerned about his visa expiring on June 5th and wants to know if he can extend it tomorrow. Comments indicate that although he is technically one day late, there may not be a penalty. However, if he stays past his expiration date, he will incur fines, especially if he does not register his residence or depending on his visa type. Extensions are possible but they may require a 500 baht fine for overstay plus fees for the extension itself.