That's a sensible solution, so the French must have learned it from someone smarter than them (which doesn't exactly narrow it down). First of all, if your employees are contracted to work certain hours, calling them outside of them is unprofessional. They're supposed to do their stuff in their working hours, if they don't they're either incompetent and they get fired, or their manager in incompetent and gets fired. Besides, you don't allow any work information on their own phones, it's bad practice, it's a security nightmare, anyone who suggests it gets fired. Last two organizations I worked with, we had clear policies: you keep anything work-related on your own devices, we fire AND sue you. You've been equipped with an Israeli-made secure phone that is worth at least 10 times any top-of-the-line commercial smartphone, you use it or we fire, sue and bury you. Your darn Israeli-made secure phone has a built-in timer that turns it off when your working time is up you log the fuck off, go the fuck home, and fuck the brains out of your wife/husband/gerbil/whatever-the-fucking-fuck. You get on with your fucking life. We don't care. You come back when it's your turn, and your fucking Israeli-made secure phone snaps on. We don't even want you to fucking charge it, because we provide you with batteries, you fucking fuck. So work, dagnabbit, work hard and then do what the fuck you want. What's your problem? Too hard for you? Are you fucking French to be that stupid?