UPDATE v1.6: Fixed bug with checkboxes disappearing when switching weeks. Sorry about that! Donations allow me to spend more time on the things I love like working on this extension. I try to fix bugs as quickly as possible but my other work still takes priority, because it's how I pay the bills :). You can help change that though! You can find the donate link in the extension menu, by clicking the extension icon in the top right of your browser window.

Added a clear button to clear all the checkboxes in case you work irregular schedules.

Added donate button to popup.