Your new on line adjustment to block or change dates available is very difficult to manage, sliding the mouse to block or open up dates is not working very well, it was much better when there was a beginning and end date available.
Also nowhere to put in days of change oner for different time os the year or length os stay as before.
Somebody needs to grab hold of your new system and sort it out.
IMO the feature to make a selection by choosing a startdate / enddate from the "calenderfields" is not removed on purpose, but probably it is missing because of a glitch. As on the multicalender the feature is still available !