pdm_ldap_import does not filter when using whenCreated argument when connecting to Novell. pdm_ldap_import will process all users in Novell.
whenCreated does not exists in Novell, only in Active Directory.
Service Desk Manager 14.1 and later
The argument to use is createTimeStamp. Example:
pdm_ldap_import -l "createTimeStamp>='20180801000000Z'"
How to query operational attributes with LDAP
Querying LDAP Operational Attributes