The mass production of clocks and watches further tightened time discipline in the Western world; before these machines were made, and made to be more accurate, it would be pointless to complain about someone's being fifteen, or five, minutes late. For many employees, the time clock was the clock that told the time that mattered: it was the clock that recorded their hours of work. By the time that time clocks became commonplace, public, synchronized clock time was considered a fact of life. Uniform, synchronized, public clock time did not exist until the nineteenth century.