Presumbaly, you also won't want people inputting anything on 30 February - ever - or 29 February in most years...

The only way you can conditionally display/hide such rows (which doesn't stop people inputting data into them) or add/delete such rows (which does stop people inputting data into them) is via a macro. Such a macro can be tied to workbook opening, so that it checks the date and adds/deletes rows as applicable.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]