Birthday Notifications
Suggestions
Actually, birthdays imported from Ning are in the User datastore (saved as user_birthdate) and are in the format yyyy-mm-dd so the above code to pick those up would be -
{$this_day = $smarty.now|date_format:"d"}
{$this_month = $smarty.now|date_format:"m"}
{jrCore_list module="jrUser" search="user_birthdate LIKE %`$this_month`-`$this_day`" limit="4"}
This will use the default user list template which is not in a grid format so you might want to add some custom user template code based on the profile grid template.
Also, add the birthday field to the User Account form, not the Profile Settings form. Add 'user_birthdate' as a text field and make the default 'yyyy-mm-dd' so as to persuade users to enter it in the right format (Also make that clear in the help text).