Twenty-Twenty-Twenty

20-20-20 is a program that alerts every 20 minutes to look something at 20 feet away for 20 seconds, written in Golang. This is done to reduce eye fadigue 1. While controversial 2, it is a simple rule to remember and can help long screen usage sessions.

How to use

In macOS just run TwentyTwentyTwenty_<arch>.app.

Warning

The releases available for macOS are signed with the adhoc certificate. They work in my build machine, but I am not sure if they work if downloaded from internet to another macOS machine. Of course, you can always build the code yourself and it should work.

Tip

Configure the notification type in "System Settings" -> "Notifications" -> "TwentyTwentyTwenty" to use "Alerts". This will result in the notification to stay until the end of the duration period instead of disappearing in a few seconds.

In Windows just run twenty-twenty-twenty-windows-<arch>.exe. You may want to disable the sounds either from the application (using the system tray) or from Windows itself (you can disable sounds for notifications from a specific application).

The second option is probably a better idea since the application play sounds when the notification starts and ends, to remind you that you can look at the screen again.

In Linux/other OS:

$ ./twenty-twenty-twenty -help
Usage of ./twenty-twenty-twenty:
  -disable-sound
        disable notification sound
  -duration uint
        how long each pause should be in seconds (default 20)
  -frequency uint
        how often the pause should be in seconds (default 1200)
  -pause uint
        how long the pause (from systray) should be in seconds (default 3600)
  -version
        print program version and exit

If you have Go installed, you can run (doesn't work in macOS though):

go run github.com/thiagokokada/twenty-twenty-twenty@latest

If you have nix installed, you can run:

nix run github:thiagokokada/twenty-twenty-twenty

How to build

Important

For macOS releases, you will need to install Xcode Command-line Tools first to sign the application:

xcode-select --install

Needs Go 1.21+.

go generate tools.go # install necessary command-line tools
make

If you have nix installed, you can also setup the development setup with it:

nix develop

Or if you have nix-direnv:

direnv allow

Optional features

You can enable/disable optional features by passing the following build tags (e.g.: go build -tags=<tag>):

• cgo: CGO is necessary for some features in some platforms. It is required for darwin, not used in windows, and enables/disables sound support in linux (and other *nix systems)
• nosound: disable sound support.
• nosystray: disable system tray support.

Credits

Notification sound 1 and Notification sound 2 by Joseph SARDIN - https://bigsoundbank.com.

Eye open extracted from Font Awesome, in SVG format from Wikipedia.