• More info:
  Not regression. This is an addition functionality for improving experience.
  This opportunity appears after adding support Expand-Collapse pattern for DateTimePicker control.

• Linked items:
  - [Accessibility] An element of the given ControlType must support the ExpandCollapse pattern for DateTimePicker control #4099 Issue
  - Adding support expand-collapse pattern for DateTimePicker #5245 PR

• .NET Core Version:
  6.0.100-rc.2.21419.27

• Have you experienced this same bug with .NET Framework?:
  Yes

Problem description:

An DateTimePicker control should announce state on Calendar opening.

Expected behavior:

An DateTimePicker control announce state on Calendar opening action. You can take a look at ComboBox control as an example.

Minimal repro:

1. Create a winforms project with a DateTimePicker control.
2. Build and run the project.
3. Launch Narrator (and Narrator Buddy optional).
4. Expand calendar using arrow-button. Collapse calendar using arrow-button or select any value in calendar.

You can detect that date-time-picker don't provide state on open calendar and provide on close. So you task to fix it.