Todo Smart Lists

Microsoft To Do's sidebar opens on smart lists that gather tasks from every list: My Day (tasks picked for today), Important (every starred task) and Planned (every dated task, grouped by when). They are the feature most people name when they describe To Do.

Why deferred

Each TodoList is its own resource with its own content blob (resources). A view across all of them means reading and parsing every TodoList blob the user owns on each open, or keeping an index of items outside the blobs — the same cross-resource content query the global calendar is deferred on, and a second source of truth the resource references page already argues against. Within one list, the Calendar blade already answers "what is planned", and the importance sort answers "what is important".

My Day adds a per-day selection that expires at midnight — state that belongs to no single list and would need a home of its own.

Revisit when

A user keeps more than a handful of TodoLists and asks for one view across them, or the global calendar is built — whichever ships the cross-resource read first, the other rides it.