code: function(elem, date) {
  			var inst = this._getInst(elem);
  			if ($.isEmptyObject(inst)) {
  				return false;
  			}
  			date = inst.options.calendar.determineDate(date,
  				inst.selectedDates[0] || inst.options.calendar.today(), null,
  				inst.options.dateFormat, inst.getConfig());
  			return this._isSelectable(elem, date, inst.options.onDate,
  				inst.get('minDate'), inst.get('maxDate'));
  		}
docs: Determine whether a date is selectable for this datepicker.
  @memberof CalendarsPicker
  @private
  @param elem {Element} The control to check.
  @param date {CDate|string|number} The date to check.
  @return {boolean} <code>true</code> if selectable, <code>false</code> if not.
  @example var selectable = $(selector).datepick('isSelectable', date)