Date widget that allows multiple selection of dates and show the total number of selected dates

Is there still no option to select multiple dates over the entire year, and calculate number of days selected?

Maybe a calculate number field, to count?

I'm sorry to say that we still don't have one. The Date Reservation widget allows you to select multiple dates, you may consider using that and just manually count the number of selected dates. 

I have also created a new feature request on this thread about the total number of selected dates. If there are updates, you should know it here.