Conversion with StrToDateTime and TFormatSettings does not work

Question

This code should work in Delphi XE2, but it gives "not a valid date and time" error in StrtoDateTime conversion:

procedure TForm2.Button1Click(Sender: TObject);
var
  s: string;
  d: TDateTime;
  FmtStngs: TFormatSettings;
begin
    GetLocaleFormatSettings(GetThreadLocale, FmtStngs);
    FmtStngs.DateSeparator := #32;
    FmtStngs.ShortDateFormat := 'dd mmm yyyy';
    FmtStngs.TimeSeparator := ':';
    FmtStngs.LongTimeFormat := 'hh:nn';

    s := FormatDateTime('', Now, FmtStngs);
    d := StrToDateTime(s, FmtStngs);
end;

Any hints?

Rapper

BTW: The DateSeparator is only used to change the '/' in Format-String. To get it used you have to set ShortDateFormat to 'dd/mmm/yyyy' otherwise it is useless :o) – Sola

Answer 1

If you want to convert some special DateTime-Formats you should better use VarToDateTime instead of StrToDateTime. Just have a look at the implementation of both and you will recognize, that StrToDateTime is somehow ... and VarToDateTime will ask the OS if it can't determine by itself.

This works with Delphi XE3 (but should also work with earlier versions):

procedure TForm2.Button1Click( Sender: TObject );
var
  s: string;
  d: TDateTime;
  FmtStngs: TFormatSettings;
begin
    GetLocaleFormatSettings( GetThreadLocale, FmtStngs );
    FmtStngs.DateSeparator := #32;
    FmtStngs.ShortDateFormat := 'dd mmm yyyy';
    FmtStngs.TimeSeparator := ':';
    FmtStngs.LongTimeFormat := 'hh:nn';

    s := FormatDateTime( '', Now, FmtStngs );
    d := VarToDateTime( s );
end;

Sola

Inb fact, using VarToDateTime works. Moreover, it removes the need to use the TFormatSettings structure. Thnx for all.. – Rapper

Answer 2

You have two issues

1. You can't use a WhiteSpace as DateSeparator, because the internal routines to parse the string uses this character to determine the date and time parts of the string.

2. The StrToDateTime function does not work when the months part use the mmm string, this is reported in this QC 23301

Midday