In case of merge conflict (e.g. 1:1 relation on destination patient already contains record), and merge conflict handling status (ConflictSurvivor) is "newest", the field specified in this property is used to determine which record is newest. Default value: use "lasted touched" date/time (create or updated date/time). When specified the value must refer to a DateTime field in the current table!

public string MergeNewestFieldName { get; set; }