diff --git a/lib/ui/date.js b/lib/ui/date.js
index 33506d8..c973077 100644
--- a/lib/ui/date.js
+++ b/lib/ui/date.js
@@ -145,7 +145,33 @@ export function getDateValue(element, formatter) {
  */
 export class DateSelector {
     _var = {
-        options: null
+        /**
+         * @type {HTMLInputElement}
+         * @private
+         */
+        el: null,
+        options: {
+            /**
+             * @type {boolean?}
+             * @private
+             */
+            enabled: true,
+            /**
+             * @type {string?}
+             * @private
+             */
+            minDate: null,
+            /**
+             * @type {string?}
+             * @private
+             */
+            maxDate: null,
+            /**
+             * @type {DateFormatterCallback?}
+             * @private
+             */
+            valueFormatter: null
+        }
     };
 
     /**
@@ -256,6 +282,11 @@ export class DateSelector {
         this._var.options.maxDate = date;
     }
 
+    /**
+     * @private
+     * @param {Date} date 
+     * @returns {Date | any}
+     */
     _getDate(date) {
         if (date instanceof Date && !isNaN(date)) {
             const year = date.getUTCFullYear();