No, it is not legal if you are hourly employee (paid by the hour), since the wage and labor laws require that time cards for hourly employees be accurate. Of course, if you're being paid for the same amount of hours, just split up differently, there is no harm to you, and so no reason to take action (e.g. to sue, or file a complaint with the Dept. of Labor); if you end up being shorted somehow, however, you would have a viable claim if your time is not being recorded accurately.If you are salaried, there is no legal obligation to track your time at all, so if your employer chooses to track it for internal purposes, they can track it any way they choose.