Thanks, indeed, there are many alternative NTP servers [1]. But I believe time.nist.gov is the default time server during Ubuntu installation, so there are many

Thanks, indeed, there are many alternative NTP servers [1]. But I believe time.nist.gov is the default time server during Ubuntu installation, so there are many hosts that depend entirely on time.nist.gov. [1] http://www.pool.ntp.org/en/ http://www.pool.ntp.org/en/