Around here, most factories shut down the week of the 4th of July and/or the week after Christmas for maintenance. Maintenance workers usually MUST work during this time to rebuild and repair tools, machines, and assembly lines. Sometimes something as simple as painting is done. When workers get back, production is at full steam again. If you were a factory worker, those were usually the only two weeks you had off during the year. Maintenance guys could take off anytime.