Install gbirthday by entering the following commands in the terminal:
sudo apt update sudo apt install gbirthday
Description:
birthday reminder applet
GBirthday is an applet to help you remember your friends' and contacts' birthdays. It uses the notifcation area for alerts. Data can be stored in a number of address book formats, flat file CSV and MySQL database.
Homepage: http://gbirthday.sf.net/
Version: 0.6.10-0.1
Section: universe/gnome