1. A method comprising: by a mobile-client device, determining one or more sensor signals indicative of motion associated with activities of a user of the mobile-client device; by the mobile-client device, determining a plurality of activity types that correspond to a portion of the sensor signals; by the mobile-client device, determining one or more activity periods of the user, wherein each activity period comprises a period of time corresponding to one or more activity types; by the mobile-client device, determining whether two or more of the activity periods should be combined into a single activity period, wherein the determining is based on a heuristics-type analysis based on a length of time for each of the two or more activity periods and activity types corresponding to each of the two or more activity periods; and by the mobile-client device, displaying the determined activity types on a display of the mobile-client device.