The mobile setting for users refers to the number of days in the past or future they are able to view events on their individual diaries. Viewing historical or upcoming events can be useful for users to plan their schedules around but too much information may be unnecessary or even overwhelming.
In order to define how much of their diary you would like a user to be able to view, go to 'Company settings', open the 'Users' section and select the one whose settings you'd like to edit. Once you have their profile open, go to the 'Mobile settings' tab, from here you can choose your future and past event parameters. Once you're done, click 'Save'. These details can be changed at any time.