http://www.techradar.com/news/windows-10-preview-beefs-up-do-not-disturb-feature-and-sharpens-edge-browser

Microsoft has pushed out a new preview build of Windows 10 to fast ring testers containing quite a number of changes, including work on the operating system’s do-not-disturb feature, and further tinkering with the Edge browser.

Build 17074 beefs up the Quiet Hours feature which, when turned on, prevents the user from being interrupted because they’re busy working hard (or perhaps gaming hard), only allowing notifications to come through from ‘important’ contacts or apps (and blocking the rest).