When followed below steps, DatePicker highlights two dates.

1. Launch any simple DatePicker program(From Ensemble or the simple program attached here)
2. Using "mouse" open DatePicker popup and select a date (for example 13-Nov-2025)
-> The Date in editor TextField will be shown as 11/13/2025
3. Using "Keyboard" change the date in editor to 11/15/2025, and Press "ENTER" key
4. Using mouse open the DatePicker Popup
=> Observe that two dates are highlighted (13 and 15)

Attaching screenshot, video and Simple DatePicker program