Giornata is a foolishly simple journaling system for GNU Emacs whose fundamental design is rooted in its hierarchical structure.

~/journal
├── 2024        → directory
│   ├── 01      → directory
│   │   ├── 01  → file
│   │   ├── 02
│   │   ├── ⋯
│   │   ├── 30
│   │   └── 31
│   └── 02
│       ├── 01
│       ├── 02
│       └── ⋯
└── ⋯

Giornata is merely an extension atop some of Emacs' key features as a text-editing environment, namely directory local variables and the built-in calendar. It is otherwise considered feature-complete.

It provides you with the liberty to:

• choose whatever file format pleases you;
• write your own extensions;
• use something that is aware of, and plays well with external text manipulation programs.

Giornata is really easy to get started with as it imposes absolutely nada on the writer. If you need some inspiration, you might be interested in the author's configuration.