Hi, welcome on this forum where users try to help other users.
I think you mean the mod_jem_jubilee. It shows the days which are specials e.g. birthdays or anniversary days. But it not thought to send emails to the users.
PHP 7.2.9 on different sites
JEM 2.3.0dev 2.0M and specials with Joomla! 3.9.3 stable on livesites
ja_simply, ja_purity_iii, multilingual DE EN IT FR