You need only be given access so as to be able to check the accuracy of your time card. As to where that access need be given us up to your employer. That is unless such action violates ther tems of an employment contract or union agreement. Otherwise, only having access to your time card at work is legal. The fact is that in an "at will" employment arrangement, a company can set the conditons of work much as it sees fit (absent some form of legally actionable discrimination).