Hi Johny,
Try this adjusted part of the code:
  If i > UBound(a) Then
   
    Dim lg_cob As String, f As String
    lg_cob = Format(Now, "_yyyy-mm-dd")
    f = Replace(DestFile, ".pdf", lg_cob & ".pdf")
   
    ' Save the merged document to DestFile
    If Not PartDocs(0).Save(PDSaveFull, p & f) Then
      MsgBox "Cannot save the resulting document" & vbLf & p & f, vbExclamation, "Canceled"
    End If
 
  End If
 
exit_: