1. A method, comprising: receiving athletic activity data from a device configured to be worn by a user; receiving a first user input indicating an activity time period; determining a number of activity points earned by the user and a rate at which the user earned the activity points based, at least in part, on the received athletic activity data; generating, on a display device, a first interface indicating a progress of the user toward achieving an activity milestone; modifying a first attribute of the first interface in accordance with the rate at which the user earned the activity points; and determining, at a processor, whether the user has achieved the activity milestone based, at least in part, on the number of activity points earned by the user during the activity time period.