Facebook has recently introduced a new group of settings to help the user manage the time they spend on its mobile app. Now, it has been augmented further with Quiet Mode, a set of toggles that allows notifications to be silenced for all or a specific part of the day. They may be followed by even more granular controls in the future.
https://www.notebookcheck.net/Facebook-introduces-a-Quiet-Mode-for-its-iOS-and-Android-app.461034.0.html