[Solved] ScanDateTime error in Sep
lazarus / 21-General

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ALAU2007 · 2025-06-09 02:39

I convert string '01 Sep 2025' to date, it shows:

  Can't match any allowed value at pattern position 4, string position
4

The other month is OK, only the Sep has error:

procedure TForm1.Button1Click(Sender: TObject);
var tDate: TDateTime;
begin
  tDate := scandatetime( 'dd mmm yyyy', '01 Jan 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 sep 2025' );  // Error
  ShowMessage( DateToStr( tDate ));
end;

Please comment.

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dsiders · 2025-06-09 03:51

Quote from: ALAU2007 on June 09, 2025, 04:39:07 amI convert string '01
Sep 2025' to date, it shows:

  Can't match any allowed value at pattern position 4, string position
4

The other month is OK, only the Sep has error:

procedure TForm1.Button1Click(Sender: TObject);
var tDate: TDateTime;
begin
  tDate := scandatetime( 'dd mmm yyyy', '01 Jan 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 sep 2025' );  // Error
  ShowMessage( DateToStr( tDate ));
end;

Please comment.

Does you system use English month names in
FormatSettings.ShortMonthNames? Cause that's what you told
ScanDateTijme() to look for.

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paweld · 2025-06-09 04:41

As @dsiders wrote, probably your system's regional settings are not
English. You need to define an array of short month names in English
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses 
DateUtils; procedure TForm1.Button1Click(Sender: TObject);var  s:
String;  dt: TDateTime;  fs: TFormatSettings;begin  fs :=
DefaultFormatSettings;  //if your system locale is not in English,
then you need to define short month names  fs.ShortMonthNames[1] :=
'Jan';  fs.ShortMonthNames[2] := 'Feb';  fs.ShortMonthNames[3] :=
'Mar';  fs.ShortMonthNames[4] := 'Apr';  fs.ShortMonthNames[5] :=
'May';  fs.ShortMonthNames[6] := 'Jun';  fs.ShortMonthNames[7] :=
'Jul';  fs.ShortMonthNames[8] := 'Aug';  fs.ShortMonthNames[9] :=
'Sep';  fs.ShortMonthNames[10] := 'Oct';  fs.ShortMonthNames[11] :=
'Nov';  fs.ShortMonthNames[12] := 'Dec';  //  s := '01 Jan 2025';  dt
:= ScanDateTime('d mmm yyyy', s, fs);  ShowMessage(DateToStr(dt)); 
//  s := '01 sep 2025';  dt := ScanDateTime('d mmm yyyy', s, fs); 
ShowMessage(DateToStr(dt));end;

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ALAU2007 · 2025-06-09 08:56

Thanks paweld and dsiders.

After defining the ShortMonthName, It works.  BTW, I have tried the
other months is OK, except the "Sep" has the error.  I have tried as

procedure TForm1.Button1Click(Sender: TObject);
var tDate: TDateTime;
begin
  tDate := scandatetime( 'dd mmm yyyy', '01 Oct 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Nov 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Dec 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Aug 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Jul 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Jun 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 May 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Apr 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Mar 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Feb 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 Jan 2025' );
  tDate := scandatetime( 'dd mmm yyyy', '01 sep 2025' );
  tDate := formatdatetime( 'dd mmm yyyy', '01 sep 2025' );   // only
it has error when shortMonthNme is not defined.
  ShowMessage( DateToStr( tDate ));
end;

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cdbc · 2025-06-09 09:45

Hi
Just an observation:
- I believe the 'ScanDateTime' function is case-sensitive:Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i   tDate :=
scandatetime( 'dd mmm yyyy', '01 sep 2025' );That would mean 'sep' is
different from 'Sep'!
I noticed all the other months were with a versal, e.g.: '(J)an' -->
not '(j)an'.
Regards Benny

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paweld · 2025-06-09 10:05

@cdbc: is not case-sensitive - uses the function:
https://docs.freepascal.org/docs-html/rtl/sysutils/ansistrlicomp.html

Edit:
@ALAU2007: you may want to check how you have short month names
defined, such as:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses 
DateUtils; procedure TForm1.FormCreate(Sender: TObject);var  i:
Integer;  s: String;begin  s := '';  for i :=
Low(DefaultFormatSettings.ShortMonthNames) to
High(DefaultFormatSettings.ShortMonthNames) do    s := s + Format('%2d
-> %s'#13#10, [i, DefaultFormatSettings.ShortMonthNames[i]]); 
ShowMessage(s);end;