Microsoft has released Windows 10 Insider Preview Build 19564 to Insiders in the Fast ring. The new build offers a preview of the new Windows 10 Calendar app and an improved Graphics settings page. The most notable changes found in this new build are detailed below. The full release notes and fixes for this Windows 10 insider build can be read in the blog post below. If you are a Windows Insider, you can update to the latest build by going into Settings -> Update & Security -> Windows Update.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-insider-build-19564-released-with-new-calendar-app-gpu-settings/