I don't know of a Calendar panel. But there is an example panel that shows how to run an event at a specific time.
Download the panels in this post: https://support.rossvideo.com/hc/en-us/community/posts/360065970252-Free-DashBoard-Example-Panels-for-Everyone
Under the "tasks" folder, there is a panel called: Running A Task At a Specific Time.grid.
It will show you how to run a task at a specific time.
I know this is a lot less than what you are asking for, but it's a starting point.
#DashBoard