etm is an acronym for event and task manager. In contrast to most calendar/todo applications, creating items (events, tasks, and so forth) in etm does not require filling out fields in a form. Instead, items are created as free-form text entries using a simple, intuitive format and stored in plain text files. Both a graphic user interface based on Tkinter and a command line interface are provided.
I have used etm for years and for the past year or so etmtk. Etmtk on Debian is better than etm for my purposes. Even though I haven't yet learned to use all its function, I can't say enough (good) about the program. It is the best time-keeper, billing and calendaring program for lawyers, hands down, regardless of price. It also does much, much more and, once learned, constitutes an environment in which one performs his daily tasks, both work-related and personal. It is an effective case management tool as well. Etm also warns you when a deadline is approaching and perhaps just as important, pursuant to its "getting things done" philosophy, refuses to clutter your day with tasks that don't yet need to be addressed. Congrats to Dan Graham and his assistants for moving the software envelope forward. The program was not easy for me, a non-nerd, to learn but the rewards were WELL WORTH the time involved. Simply put, it is not easy to learn because organizing one's life is not an easy thing to do, at least for disorganized folks like this reviewer. But remember, one need not use all of Etm's many features to gain considerable assistance. Just start using it and add functionality as you go.