Digital calendars matter because they mediate our understanding of time in both professional and social contexts. We usually don’t think twice about the design of these tools because they’re the invisible “water we swim in.” But their default settings/visualizations are shaping how we treat our time and others’—for the worse.

The original sin of digital calendars is that they’re blank by default. All white. Waiting to be “colored in” with the events of your life. The blank-by-default style of representing time implies that your time is not accounted for. Empty wasteland. Nothing to see here. This is an especially bad default in the corporate world, where Gcal has turned private calendars into a shared commons. Anyone can easily pull up your schedule, and the blankness-by-default is an open invitation to take away your time.

— Aaron Lewis, Fools and their time metaphors