diff --git a/src/case/calendar/calendar.js b/src/case/calendar/calendar.js
index 88ccf198a..0a9d40e05 100644
--- a/src/case/calendar/calendar.js
+++ b/src/case/calendar/calendar.js
@@ -156,13 +156,21 @@ BI.Calendar = BI.inherit(BI.Widget, {
         return BI.map(items, function (i, item) {
             return BI.map(item, function (j, td) {
                 var month = td.lastMonth ? o.month - 1 : (td.nextMonth ? o.month + 1 : o.month);
+                var year = o.year;
+                if (month > 12) {
+                    month = 1;
+                    year++;
+                } else if (month < 1) {
+                    month = 12;
+                    year--;
+                }
                 return BI.extend(td, {
                     type: "bi.calendar_date_item",
                     once: false,
                     forceSelected: true,
-                    value: o.year + "-" + month + "-" + td.text,
+                    value: year + "-" + month + "-" + td.text,
                     disabled: td.disabled,
-                    cls: td.lastMonth || td.nextMonth ? "not-current-month-day": "",
+                    cls: td.lastMonth || td.nextMonth ? "not-current-month-day" : "",
                     lgap: 2,
                     rgap: 2,
                     tgap: 4,