When is an extremely simple personal calendar program, aimed at the Unix geek
who wants something minimalistic. It can keep track of things you need to do on
particular dates. There are a lot of calendar and "personal information manager"
programs out there, so what reasons are there to use When?

- It's a very short and simple program, so you can easily tinker with it
  yourself.
- It doesn't depend on any libraries, so it's easy to install. You should be
  able to install it on any system where Perl is available, even if you don't
  have privileges for installing libraries.
- Its file format is a simple text file, which you can edit in your favorite
  editor.

WWW: https://www.lightandmatter.com/when/when.html
WWW: https://github.com/bcrowell/when