Do genitive dates always work properly for Greek?

About a year ago I talked about "What the %$#! are genitive dates?" and a little while ago I talked about them again.

We are facing an interesting question right now when it comes to genitive dates in the .NET Framework.

It all boils down to reports that the behavior for genitive dates may be different in some cases for these other platforms. But before we can even investigate the potential changes or when they could happen, we have to know if there is a problem for sure.

My hope is that native speakers of Greek who see this article can give their thoughts on this issue. :-)

If you are a native speaker of Greek then you most likely know about the nominative and genitive forms of the month names. Using similar to this post code I got the following results:

E:\test>csc BUG.cs
Microsoft (R) Visual C# 2005 Compiler version 8.00.50727.42
for Microsoft (R) Windows (R) 2005 Framework version 2.0.50727
Copyright (C) Microsoft Corporation 2001-2005. All rights reserved.

E:\test>chcp 1253
Active code page: 1253

E:\test>BUG.exe
Ιανουάριος      Ιανουαρίου          Σάββατο, 1 Ιανουαρίου 2005
Φεβρουάριος     Φεβρουαρίου         Τρίτη, 1 Φεβρουαρίου 2005
Μάρτιος         Μαρτίου             Τρίτη, 1 Μαρτίου 2005
Απρίλιος        Απριλίου            Παρασκευή, 1 Απριλίου 2005
Μάιος           Μαΐου               Κυριακή, 1 Μαΐου 2005
Ιούνιος         Ιουνίου             Τετάρτη, 1 Ιουνίου 2005
Ιούλιος         Ιουλίου             Παρασκευή, 1 Ιουλίου 2005
Αύγουστος       Αυγούστου           Δευτέρα, 1 Αυγούστου 2005
Σεπτέμβριος     Σεπτεμβρίου         Πέμπτη, 1 Σεπτεμβρίου 2005
Οκτώβριος       Οκτωβρίου           Σάββατο, 1 Οκτωβρίου 2005
Νοέμβριος       Νοεμβρίου           Τρίτη, 1 Νοεμβρίου 2005
Δεκέμβριος      Δεκεμβρίου          Πέμπτη, 1 Δεκεμβρίου 2005

E:\test>

Ok, as you can see the genitive forms are used for this format string every time.

The report that was received received was that for Greek both forms are acceptable, though possibly using the genitive form as above is considered more formal. An informal style might use the nominative form, instead.

Now it is unclear how often in an informal communication or email you would be using full date formats like this one, so perhaps it is not an issue that people would often notice as being a problem. But the questions for any readers of this post who are native speakers of Greek are:

1. Is the above an accurate description of the usage?
2. Is there a definite, understandable benefit to exposing both types of usage in the formatting string?
3. Approximately what percentage of dates that you might format for a computer would be expected to be in each form?

This post brought to you by "ς" (U+03c2, a.k.a. GREEK SMALL LETTER FINAL SIGMA)