Please add this code int the booking form at the Booking > Settings > Form page, for ability to deselect dates in calendar by clicking on "Deselect" button:

	<a href="javascript:void(0)" onclick="javascript:reset_days_selection( this );" class="btn">Unselect Dates</a>
	<script type="text/javascript">
			function reset_days_selection( el ) {
				var br_id = jQuery( el ).closest( 'form' ).find( 'input[name^="bk_type"]' ).val();
				wpbc_unselect_all_days( br_id );
				if( typeof( showCostHintInsideBkForm ) == 'function' ) {  showCostHintInsideBkForm( br_id ); }
			}
   </script>