Our Night Mode can eliminate that problem. Night Mode automatically disables the sound of all notifications from 12 Midnight-8am in your time zone.  This is a default setting.  However,if you still receive notifications during the night, please check that it's enabled.  Youcan do soby accessing the left-side menu and tapping Settings and then Notifications.  The ON/OFF icon next to Night Mode indicates if Night Mode is enabled or disabled.