Issue:

The date columns are filled with 01 Jan 1970 01:00:00.000000 instead of being empty.

Root Cause:

ServiceDesk Upgrade did not handle it

Solution:

Add the entry " ZOHO_UPDATE_NULL_FOR_NEGATIVEVALUE=true" in <SDP_HOME>\zreports\uploadtool\conf\common_params.conf

Hit re-sync button.

Note: ServiceDesk Plus restart not necessary.