Time Switch is a free and open source system timer app for Linux. Using Time Switch you can power off, reboot, suspend your computer on timer. Not only this you can also send a notification with a sound signal on timer. It is written in Python and still in early stage of development. It is a simple and easy to use app.
How to Install Time Switch on Ubuntu
Time Switch is available as a flatpak package from flathub. First install flatpak and flathub on your system and restart it after the installation. Follow below link for the installation instructions.
In the terminal app run below Time Switch flatpak command to install it. You can open terminal app using ctrl+alt+t keys.
flatpak install flathub io.github.fsobolev.TimeSwitch
You can open it using below command.
flatpak run io.github.fsobolev.TimeSwitch
And uninstall Time Switch using this command.
sudo flatpak uninstall io.github.fsobolev.TimeSwitch