You may use the following commands, run as an administrator in Windows PowerShell, to configure the Network Time Protocol (NTP) settings for Microsoft Windows Server 2012 R2. In this example, the NTP server to be configured is pool.ntp.org, which is a round-robin of NTP server.

w32tm /config /manualpeerlist:pool.ntp.org /syncfromflags:MANUAL
Stop-Service w32time
Start-Service w32tim

Enjoy!