This appears to be the way to configure Windows 2008 R2 Server Core as an NTP client (replace the all caps bits with the appropriate values):
w32tm /config /computer:COMPUTER_NAME /manualpeerlist:NTP_SERVER_FQDN /syncfromflags:manual /update
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This appears to be the way to configure Windows 2008 R2 Server Core as an NTP client (replace the all caps bits with the appropriate values):
w32tm /config /computer:COMPUTER_NAME /manualpeerlist:NTP_SERVER_FQDN /syncfromflags:manual /update