Orage
Calendar for Xfce Desktop Environment
Orage aims to be a fast and easy to use graphical calendar. It uses portable ical format and includes common calendar features like repeating appointments and multiple alarming possibilities.
Orage does not have group calendar features, but can only be used for single user. It takes a list of files for ical files that should be imported. Contents of those files are read and converted into Orage, but those files are left untouched.
This package contains a calendar for the Xfce4 desktop environment. It integrates itself nicely into the desktop environment, is highly configurable and supports alerts based on dates. If you are looking for a good graphical calendar, you will probably want to try out orage. It stores its data in iCal format.
How to install Orage in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install orage in Ubuntu
sudo apt install orage