Why does the local playback prompt 'No recorded files on that day'?

When no recordings exist for a selected date, users can access the "Calendar" feature to choose an alternative day. The calendar interface distinguishes dates containing recorded files through darkened highlighting.

Steps:

1. Observe the "No recorded files on that day" message
2. Click the "Calendar" option
3. Select a different date
4. Look for darker-colored dates, which indicate available recordings