No, you are not required to do this unless required to do so by court process (such as by a subpoena, if you are subpoenaed) or otherwise in litigation (such as if you are sued by the employee and he requests them via a document production request or written interrogatories). Otherwise, the time cards may be about him but they are your company's property, and you are not obligated to share them with him. Alternately, you could offer to provide them, if he pays the hourly cost of a staff member to copy them and the cost of copies; if you want to make this offer, make sure he gives you a deposit for the cost in advance.