Heh funny, I started writing a "labbook" like this ~6 months ago with markdown writer in atom for every day. I have a background as a Lab technician where I was used to keep a daily detailled labbook so I didn't have to develop that habit..
I like to structure my programming lab book in a similar way, for every task/ bug/ project I try to jot down a description, hypothesis, expected outcome and document my progress with code snippets / outputs / plots. I also keep a Todo list at the top to visualize my current workload. It really helps if you have to come back to a problem later on or just to get a good overview of your current task. I feel lik this also works nicely in conjuncture with GTD to increase my productivity.
I like to structure my programming lab book in a similar way, for every task/ bug/ project I try to jot down a description, hypothesis, expected outcome and document my progress with code snippets / outputs / plots. I also keep a Todo list at the top to visualize my current workload. It really helps if you have to come back to a problem later on or just to get a good overview of your current task. I feel lik this also works nicely in conjuncture with GTD to increase my productivity.