Time provides a universal and conserved measurement. Everyone has 24 hours in a day and spends each moment of it doing something, adding up to about 200 billion hours daily. The choice of activities determines the emergent outcomes for our planet and society. Climate change, biodiversity loss, and infrastructure development are all examples of outcomes arising from our collective actions across the planet. At the same time, the subjective experience of life depends on what people do, and the context in which they do it. But despite their importance, there have been few comprehensive assessments of human activities globally.

There is no universal way to describe human activities, and prior data collection efforts have been tailored towards particular objectives. As a result, existing time-use data describe human activities using some combination of dimensions, which could include physical outcomes, technology use, social context, or contact with nature. The Chronome project tackles this challenge by linking activities to generalized lexicons that focus on single dimensions of activity. This allows for transparent and unambiguous simplification of the otherwise incredibly complex phenomenon of human behaviour. Identifying and classifying based on single dimensions at a time allows for activities to be linked to external variables such as material end uses, screen time, and wellbeing.