At a high level, a productive day means you had few meetings (ideally grouped together) and 3 or more hours of focus time broken up by small breaks. Below is a visual example of what this looks like via the timeline:
The large purple blocks in the timeline indicates tracked time—time when you are actively working on your computer. The horizontal bars underneath indicate whether you spent that time in a meeting (pink), focusing on work (blue), or doing shallow work (no bar).
Notice how the timeline above has large blocks of uninterrupted time for focus with consistent breaks to stay refreshed and recharged. Studies show that taking frequent breaks while trying to complete intense cognitive tasks drastically improves your performance. This is the reasoning behind productivity methodologies like the Pomodoro technique.
Rize also represents focus time, meetings, and breaks as a percentage of your hours worked for the day:
Realistically, there are many factors out of your control that affect your day. However, understanding what a good day looks like can help you look at each day and see where things can be improved.