GNOME Shell extension placing an icon in status area with a simple slider for fast and easy setup of scheduled shutdown.
Heavily based on Lukas Knuth's Backslide code at https://bitbucket.org/LukasKnuth/backslide
Unzip the archive so that the shutdowntimer@lusk.cz folder is in ~/.local/share/gnome-shell/extensions
There are no notifications sent reminding that the timer is running. If the Even with unsaved documents toggle is enabled there is not even a shutdown dialog. But who cares, you are already sleeping at that moment, right? :)