In the state of Massachusetts, the same as many other states, you are entitled to one day of rest, a 24-hour amount of time for every 7 days in a row. This 7-day period does not have to be a Saturday through Sunday or Sunday through Saturday, it can take place at any time; so if you start working for a company on a Tuesday then your work week might run through the following Monday in which case you are legally required to have one full day off in between work.