Yes. You can use NinjaCal to help filter portals by date range. This is a great alternative to requiring users to type in a date range as NinjaCal will always visually display the range being filtered.
Check out the Date Range Filters tab in the NinjaCal example file for a working example of such portal filtering.
Since NinjaCal can select discontiguous dates, we don't use traditional date ranges when filtering portals with NinjaCal (that is, we don't use ≤ and ≥ operators in our relatinships). Rather, NinjaCal converts the selected dates into numbers and compares those with the dates in your table. This means you'll likely need to add a new calculation field to your dates table which will convert that date into a number. You can use the field "ApptDateAsNumber" in our SampleAppointments table as an example.