Master clocks can use hardware time references, such as the GPS system to obtain very precise time. GPS is accurate to one-second in three hundred million years. Therefore, all time displays and slave clocks can refer to a highly accurate, legally traceable source of time. GPS systems require an antenna that is typically located with a clear view of the sky. Alternatively, where antenna installation is difficult, public internet Network Time Protocol (NTP) servers can be used.
Many organizations can benefit from synchronized clocks. Staff all work to the same time, therefore meetings can start promptly, classes in schools start and finish as scheduled and shifts start and end consistently. Hospitals, manufacturing and pharmaceutical industries can accurately log events.