Sharepoint doesn't like users who are born Februari 29th [ http://support.microsoft.com/default.aspx?scid=kb;en-us;936912 ]
Error message when you enter February 29 in the
"Birthday" field in SharePoint Server 2007: "The date you have entered
is not in a valid format"
SYMPTOMS
You visit the
View User Profiles Web page in the SharePoint Shared Services Administration Web site in Microsoft Office SharePoint Server 2007. You enter
February 29 in the
Birthday field, and then you click
Save and Close. When you do this, you receive the following error message:
The
date you have entered is not in a valid format, or it is outside of the
valid range of dates. Reenter a valid date in the format May 03
CAUSE
This
behavior occurs because SharePoint Server 2007 does not support
February 29 as a birthday value. This is because most users who have
birthdays that occur on February 29 select February 28 or March 1 as
their annual birthday. Additionally, birthdays that occur on February
29 do not work correctly in non-Gregorian calendars.
WORKAROUND
To work around this behavior, you must enter February 28 or March 1 as the birthday value.
STATUS
This behavior is by design.