TFileTime -> TDateTime

function FileTimeToDateTime(FileTime: TFileTime): TDateTime;
 var
   ModifiedTime: TFileTime;
   SystemTime: TSystemTime;
 begin
   Result := 0;
   if (FileTime.dwLowDateTime = 0) and (FileTime.dwHighDateTime = 0) then
     Exit;
   try
     FileTimeToLocalFileTime(FileTime, ModifiedTime);
     FileTimeToSystemTime(ModifiedTime, SystemTime);
     Result := SystemTimeToDateTime(SystemTime);
   except
     Result := Now;  // Something to return in case of error 
  end;
 end;

 function DateTimeToFileTime(FileTime: TDateTime): TFileTime;
 var
   LocalFileTime, Ft: TFileTime;
   SystemTime: TSystemTime;
 begin
   Result.dwLowDateTime  := 0;
   Result.dwHighDateTime := 0;
   DateTimeToSystemTime(FileTime, SystemTime);
   SystemTimeToFileTime(SystemTime, LocalFileTime);
   LocalFileTimeToFileTime(LocalFileTime, Ft);
   Result := Ft;
 end;