In drupal 5 and Views 1 we had an possibility to add separately filters for each component of the date field.
For the displaying list of users birthday today (in drupal 5 and views 1) I added the next filters:
month == now
day == now
and the year is unimportant.
in drupal 6 and views 2 I cant add separately filters, I just can add date field completely including the year.
Certanly it doesnt allow me to create the birthdays today list.
After all, those who was born in 2009 hardly will manage to be registered on a site.)))