Inverse function of FormatDateTime

Question

I am looking for a function to reverse any string (YYYYMDD,YY/MM/DD,YYMMDD,...) created by the function FormatDateTime to

Answer 1

Function InvFormatDatetime (Cadena:String; Formato:String) : TDateTime;

Var
  PosD, PosM, PosY : Integer;
  sD, sM, sY       : String;

begin

  sd := '0';
  sm := '0';
  sy := '0';

  If Length(Cadena) = Length(Formato) Then
    Begin
      Formato := UpperCase(Formato);
      PosD := Pos('D',Formato);
      PosM := Pos('M',Formato);
      PosY := Pos('Y',Formato);

      sd := Copy(Cadena,PosD,2);
      sm := Copy(Cadena,PosM,2);

      if Length(Cadena) = 6 then
        begin
          sy := Copy(Cadena,PosY,2);
          if StrToInt(sy) > 50 then
            sy := '19'+sy
          else
            sy := '20'+sy;
        end
      else
        sy := Copy(Cadena,Posy,4);
    End;
  Result := EncodeDate(StrToInt(sY),
                       StrToInt(sM),
                       StrToInt(sD));
End;

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