Date Picker Range Across Months

[DarMontou]

Is your feature request related to a problem? Please describe.

When selecting a range across months we show the days from the prior month in the calendar but do not indicate that they're included.

Describe the solution you'd like
Some sort of visual indication that the days from the prior month are in the selection.

Additional context
The visual indication should be more subtle than the indication for the current month.