Var
  tmpDate: TDateTime;
  tmpStrip: TStringList;
Begin
  psVSA := psFileName;
  psExitCode:= 0;
  // ... add your code here
  (*
  Original Filename: 2023-10-24_section_A2.pdf
  (2023-10-24 = October 24, 2023)
  Rename To:  Tues_2023-10-24_section_A2.pdf
  *)
  tmpStrip := TStringList.Create;
  tmpStrip.Delimiter := '_'; tmpStrip.QuoteChar := #0; tmpStrip.StrictDelimiter := True;
  tmpStrip.DelimitedText := psFileName;
  if tmpStrip.Count >= 1 Then
  Begin   
    tmpDate := psStrToDate(tmpStrip.Strings[0], 'YYYY-MM-DD', '-');
    If tmpDate <> 0 Then    
    Begin
      psVSA := FormatDateTime('DDDD', tmpDate) + '_' + psFileName;
      psLogWrite(1, '', 'Filename Result: ' + psVSA);      
      psExitCode := 1;  
    End
    Else
      psLogWrite(1, '', 'Not a valid datepart in filename: ' + psFileName); 
  End
  Else
    psLogWrite(1, '', 'Not a valid filename to strip parts from: ' + psFileName);
End.