You will need to check in your Sig Server first.
SSH CLI to Sig Server and enter : ntpconfig
Enter ntp server details as appropriate, then go into CS1K:
LD 117
STAT NTP
&
PRT NTP
You should be pointing in LD 117 to your Sig Server that the NTP has been configured.
If it is not, probably easiest to go to Element Manager and setup NTP.