"Clock out" button for mobile app, or something to disable notifications

It would be useful to have a "clock out" feature in the mobile app, so that an agent can log out without actually logging out. We use very secure passwords (24 random characters) and logging in and out is a time consuming process. A simple button that keeps the user credentials stored, but logs him out would be beneficial, so that agents won't receive new customer requests at midnight. Next day, clicking the same button would log the agent back in, without him having to spend time re-typing the long password.