To sync your time with a known local timeserver/domain controller, open up CMD (preferably with administrative privileges) and type
net time timeserver /set /yes
If you instead want to sync with an external time server.
w32tm /config /syncfromflags:manual /manualpeerlist:pool.ntp.org /reliable:no /update
Another useful command to note is:
w32tm /stripchart /computer:si.pool.ntp.org /samples:5 /dataonly
this will check the difference between current time and external ntp server.