Python script alerts the user to take regular screen breaks. Three 20-minute sessions of work, one 2-minute break, one 3-minute break and one 10-minute break, all in the span of 1 hour.
git clone https://github.com/mmilan1/take-a-break.git
Run main.pyw on the command-line.
The script will run in the background and will stop after 1 hour.
Rerun the script as often as you need to.