In one example in accordance with the present disclosure a method of is described. According to the method, usage data for an electronic device is obtained. An activity phase from a plurality of activity phases for the electronic device is selected based on the usage data. An activity phase has a corresponding timeout period and is defined by an inter-arrival threshold. The electronic device is instructed to enter a low power mode after being inactive for a time period at least as great as the timeout period corresponding to a selected activity phase.