My suggestion would be; beside each person's profile picture on the top right of the app, there should be a dropdown with three options, Active(for when im at work), On break (for when i decide to go on break), Signed Out (for when i sign out of work for the day).

and you can only go on break once a day. that means when you select it once and turn it back to active, the break option is not clickable again till you sign in the next work day.