PickerOptions

Sets the default value for the DatePicker Control. The date displayed will be based on the configured default value.

In the PickerOptions, when invoking a Popup screen called by Lookup, you can press New in the Table List to add a new Table List. After selecting the added item in the Table List, you can register a Symbolic String in the Display Title or enter a Custom Title, and configure Date, Default Date, and other settings in the right detail screen.
If the Date Type is set to Range, you should configure Start ~ End.

[Image 1. After configuring the PickerOptions]