Bug in Delphi (StrToDate)?

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Tobias Mueller

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Dec 24, 2001, 8:48:30 PM12/24/01
to
Hi,

I don't exactly know wether I'm doing something wrong or if there's a bug in
Delphi so I post some sample code here. If you have any ideas on what may go
wrong please let me know.

Steps to reproduce:
-------------------------------
- Set the "Date separator" in the Regional Options in Windows|Control Panel
to "-"
- Set the "Short date format" in the Regional Options in Windows|Control
Panel to dd-MMM-yyyy
- Click OK

The "Short date sample" should look like "25-Dec-2001"

Now create a simple application in Delphi which includes just one form and
one button on it. Type in the following code for the OnClick event handler
of the button:

StrToDate(DateToStr(Date));

That's all. Everytime I try this simple code I get an exception that
24-Dec-2001 is not a valid date. Personally I would say that StrToDate
should inverse DateToStr and should work like + does to -:

1+1-1 = 1
1-1+1 = 1

because - is the inverse to +.

Thanks for any information on this topic.
- tobias (tob...@winkfz.de)

P.S.: I tried Delphi 4,5,6 on Windows 2000(de),XP(en).

P.P.S: Based on the above, there are also errors if you try to work with the
BDE with the above mentioned type of "Short date format".


Bruce Roberts

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Dec 24, 2001, 11:45:05 PM12/24/01
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"Tobias Mueller" <tob...@winkfz.de> wrote in message
news:3c27da82_2@dnews...

> Hi,
>
> I don't exactly know wether I'm doing something wrong or if there's a bug
in
> Delphi so I post some sample code here. If you have any ideas on what may
go
> wrong please let me know.

> StrToDate(DateToStr(Date));


>
> That's all. Everytime I try this simple code I get an exception that
> 24-Dec-2001 is not a valid date. Personally I would say that StrToDate
> should inverse DateToStr and should work like + does to -:

StrToDate is working as documented. The function is not the inverse of
DateToStr.

Mike Orriss (TeamB)

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Dec 25, 2001, 3:39:13 AM12/25/01
to
In article <3c27da82_2@dnews>, Tobias Mueller wrote:
> - Set the "Short date format" in the Regional Options in Windows|Control
> Panel to dd-MMM-yyyy
>

Not advisable. You will get problems if setting month to more than two
characters.


Mike Orriss (TeamB and DevExpress)


Tobias Mueller

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Dec 25, 2001, 6:45:14 AM12/25/01
to
Hi Mike,

> Not advisable. You will get problems if setting month to more than two
> characters.

Is there any workaround for this problem?

Thanks,
- tobias (tob...@winkfz.de)


Tobias Mueller

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Dec 25, 2001, 6:43:55 AM12/25/01
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> StrToDate is working as documented.
In the help file it's mentioned that MM/DD/YY, DD/MM/YY and YY/MM/DD are
allowed values for ShortDateFormat. But isn't that a "limitation", since
Windows actually does support a width range of other settings?

> The function is not the inverse of DateToStr.

From the help file (translated by me since I have the German help files):
- StrToDate: The function StrToDate converts a string to a Datevalue*
- DateToStr: The function DateToStr converts a variable of type TDateTime
into a string.

[*] Datavalue means variable of type TDateTime.

Doesn't that mean StrToDate -> converts string to date; and DateToStr ->
converts DateToStr?

Do you have any advice what should be used instead of StrToDate which is
able to handle different ShortDateFormats (as Windows is)?

Thanks,
- tobias (tob...@winkfz.de)

Rafael Santini

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Dec 25, 2001, 11:34:28 AM12/25/01
to
Yes.

See this code:

var
OldShortDateFormat: String;
begin
OldShortDateFormat := ShortDateFormat;
ShortDateFormat := 'dd-mm-yyyy';
StrToDate(DateToStr(Date));
ShortDateFormat := OldShortDateFormat;
end;

Regards,

--
/*
* Rafael Santini
* E-Mail: rafael...@terra.com.br
* ICQ 54152945
* Floripa/SC
*/
"Tobias Mueller" <tob...@winkfz.de> escreveu na mensagem
news:3c28665a$1_2@dnews...

Tobias Mueller

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Dec 25, 2001, 5:27:38 PM12/25/01
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Hi Rafael,

> ShortDateFormat := 'dd-mm-yyyy';
that's exactly what I thought first. But since I live in Germany I would set
ShortDateFormat to dd.mm.yyyy because that's the way we write a date. Now
whenever I present a date to the user it will have the format specified by
me (e.g. German). Customers in the US would be a bit upset if I print
24.12.2001 on their invoices since they are used to see 12/24/2001.

Do you have any other ideas? Thanks!

- tobias (tob...@winkfz.de)


Marjan Venema

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Dec 26, 2001, 4:41:09 AM12/26/01
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> > ShortDateFormat := 'dd-mm-yyyy';
> that's exactly what I thought first. But since I live in Germany I would set
> ShortDateFormat to dd.mm.yyyy because that's the way we write a date. Now
> whenever I present a date to the user it will have the format specified by
> me (e.g. German). Customers in the US would be a bit upset if I print
> 24.12.2001 on their invoices since they are used to see 12/24/2001.

I think you missed the

OldShortDateFormat := ShortDateFormat;

and the

ShortDateFormat := OldShortDateFormat;

surrounding the explicit assignment of 'dd-mm-yyyy' to the ShortDateFormat.

Marjan
_________________________
Marjan Venema - BJM Software
in...@bjmsoftware.com
http://www.bjmsoftware.com


Tobias Mueller

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Dec 26, 2001, 5:21:16 PM12/26/01
to
yup thanks. Sorry, missed that one.

Hopefully, everyone who ever build a component used this technique ;)

- tobias (tob...@winkfz.de)


Gokcan Meta

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Sep 4, 2020, 5:06:06 AM9/4/20
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25 Aralık 2001 Salı tarihinde saat 13:43:55 UTC+2 itibarıyla Tobias Mueller şunları yazdı:
Thank u so much Tobias :) This information has helped me a lot!!! year: 2020 hahahah
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