When the feature is activated from a parent's account, the app will be inaccessible by the kids, blocking off access to sending or receiving messages or video calls and the rest of the app's functionality. Facebook says the "off times" can be changed whenever you see fit.

This likely won't quell the voices saying that kids shouldn't have access to such technology in the first place. Or, do anything to assuage the worry that so much digital communication at an early age could have a dire impact on childhood development, of course. But, if you're keen to stick a smart device in your kid's hand, now you'll have a little more control over when they can use one aspect of it.