This applet will sit in your panel and countdown the time left until your estimated time of death based on your life expectancy.
- Download the zip from this page
- Unzip and extract into ~/.local/share/cinnamon/applets/mementomori@kogs
- Enable the applet in System Settings -> Applets
- You can access the Settings Screen from System Settings -> Applets or from the Applet's Context menu
- Open the preferences to enter your birth date and life expectancy.
- I personally used https://calcuworld.com/health-calculators/life-expectancy-calculator/ but you can search the web for other calculators.