An algorithm to synchronize the time of a computer to universal time
Judah Levine · IEEE/ACM Transactions on Networking · 1995
Describes an algorithm that synchronizes the time of a computer clock to UTC with an uncertainty due to all causes of about 1 ms RMS. The method uses periodic calibration data obtained via dial-up telephone access to the NIST automated computer time service. The interval between calibrations can be chosen to provide optimum time accuracy or reduced accuracy at reduced cost based on a preliminary evaluation of the statistical performance of the clock. The computer can serve as a primary network time server or can be used stand-alone whenever precise time-stamps are required.>