For non-exempt employees, yes, well established, black letter Federal law that you cannot avoid specifies that you must keep track of each and every hour worked. It does not have to be by time clock but it has to be done by some method and it has to be done accurately. There is NO getting out of this one.

Federal law does not require that you keep track of exempt hours worked, though I have heard rumors that one or two states require it. To my knowledge CO is not one of them. Mlane?

Although it is not required for exempt employees, neither is it prohibited and there are some good and valid reasons for doing so.