It is recommended that you set the NTP clock source, the time zone and time during initial configuration. If you set the NTP clock source in other phases, severe consequences may occur, for example, the video recording time may be inconsistent across cameras, recordings cannot be properly played, or alarms cannot be queried. Changing the NTP clock source, the time zone or time may restart the IVS servers that time-synchronize with the NTP clock source server. Exercise caution when performing this operation.
Otherwise I agree with @Nasr. the ideal is to have an independen****P server