Time-use surveys are the primary statistical vehicle for recording information on how people precisely allocate their time across different day-to-day activities. Typically, a large number of people keep a diary of activities over one or several representative days for a given period. Respondents describe their activities in their own words in a time diary and these are then re-coded by national statistical agencies into a set of descriptive categories. A well-designed survey classifies activities across a total duration of 24 hours (or 1 440 minutes) per day. Interest in time-use studies has grown considerably over the last 30 years and an increasing number of national statistical agencies have been conducting large-scale time-use surveys