Hi Erkki, thanks for reporting.

Please could you verified if it is same issue as here:
https://bugs.freedesktop.org/show_bug.cgi?id=74869

Created attachment 94615 [details]
Bug shown in a Calc document

May 1st is missing for the year 1921.
Instead 2 times 30.4.1921.

May 1st is present at other years.

Hi

I do not think that Bug 75404 is the same as Bug 74869.

I addes a file to the bug report.

Best regards Erkki

23.2.2014 20:00, bugzilla-daemon@freedesktop.org kirjoitti:
> m.a.riosv <mailto:mariosv@miguelangel.mobi> changed bug 75404
> <https://bugs.freedesktop.org/show_bug.cgi?id=75404>
> What 	Removed 	Added
> Status 	UNCONFIRMED 	NEEDINFO
> CC 	  	mariosv@miguelangel.mobi
> Ever confirmed 	  	1
> 
> *Comment # 1 <https://bugs.freedesktop.org/show_bug.cgi?id=75404#c1> on
> bug 75404 <https://bugs.freedesktop.org/show_bug.cgi?id=75404> from
> m.a.riosv <mailto:mariosv@miguelangel.mobi> *
> 
> Hi Erkki, thanks for reporting.
> 
> Please could you verified if it is same issue as here:
> https://bugs.freedesktop.org/show_bug.cgi?id=74869 <show_bug.cgi?id=74869>
> 
> ------------------------------------------------------------------------
> You are receiving this mail because:
> 
>   * You reported the bug.
>

Please don't answer through the email, usually makes unreadable the report, if you can answer here with a new comment, and you can attach the sample files here.

Also please report what is the User Interface that you are using and what is your time zone?

This problem is visible in 
Windows 7, 64 bit Finnish language
LibreOffice 4.1.5.3 Finnish language
Time Zone UTC+2 Helsinki

Problem is also visible in Windows 8, 64 bit, Finnish
LibreOffice 4.1.4.2 Finnish language
Time Zone UTC+2 Helsinki

Problem does not appear in Windows XP, 32 bit
LibreOffive 4.0.4.2
Same languages and time zone as above.
Nor it did not show up in Linux Ubuntu Live CD 12.04.4

Created attachment 94685 [details]
Screenshot how I see.

As in the attached screenshot, I can't reproduce the issue, with Finnish UI+locale and time zone Helsinki.

Please try resetting the user profile, sometimes solve strange issues.

Just to complete the Mario's comment, you'll find more information about LO directory profile here:
https://wiki.documentfoundation.org/UserProfile

Thanks Julien, I forgot the link.

Hi
I did resetting of the user profile.
No help. The same behavior still.
It is enough you type the date 1.5.1921 (day.month.year) in a cell in LibreOffice CALC and immediately when clicking with mouse elsewhere the cell contents turns to 30.4.21 or 30.4.1921.

I have made a few other tests with other computers.
The same problem with 
Windows 8.1 64 bit, Swedish language, 
LibreOffice 4.2.1.1, Swedish language
This is a fresh installation, the whole PC is only 4 days old.
Time zone UTC+2 Helsinki

Also the same problem with normally installed Linux Ubuntu 12.04.4
Fresh installation mid February 2014 to that level, all updates installed after installation.
Finnish language, time zone UTC+2 Helsinki.

All LibreOffice Windows installation are from here http://fi.libreoffice.org/ 

Br Erkki

Forgot to say that the Linux Ubuntu 12.04.4 is 32 bit version.

Created attachment 95114 [details]
Time zone UTC+2 Helsinki, Kiev, Riika, Tallinna, Vilna

I made a few tests again.
Appeared that the problem exists (in Windows 7) if the time zone is UTC+2 Helsinki, Kiev, Riika, Tallinna, Vilna.

When I changed the time zone to anything else, even to e.g. UTC+2 Jerusalem, there is no problem in CALC.

Attached 2 screenshots.

I have not tested with Linux.

Created attachment 95115 [details]
Time zone UTC+2 Jerusalem

Then I think it is same issue, at least the same root as in https://bugs.freedesktop.org/show_bug.cgi?id=74869, OS time zone affects some dates.

Please if you are not agree, reopen it.

*** This bug has been marked as a duplicate of bug 74869 ***