DateBox: Use UTC units to get correct date, if date is just a year string (T1323373)

packages/devextreme/js/__internal/core/utils/m_date_serialization.ts

@@ -7,9 +7,9 @@ const NUMBER_SERIALIZATION_FORMAT = 'number';
 const DATE_SERIALIZATION_FORMAT = 'yyyy/MM/dd';
 const DATETIME_SERIALIZATION_FORMAT = 'yyyy/MM/dd HH:mm:ss';
 
+const ISO_PARTIAL_DATE_PATTERN = /^\d{4,}(-\d{2})?$/;
 const ISO8601_PATTERN = /^(\d{4,})(-)?(\d{2})(-)?(\d{2})(?:T(\d{2})(:)?(\d{2})?(:)?(\d{2}(?:\.(\d{1,3})\d*)?)?)?(Z|([+-])(\d{2})(:)?(\d{2})?)?$/;
 const ISO8601_TIME_PATTERN = /^(\d{2}):(\d{2})(:(\d{2}))?$/;
-
 const ISO8601_PATTERN_PARTS = ['', 'yyyy', '', 'MM', '', 'dd', 'THH', '', 'mm', '', 'ss', '.SSS'];
 const DATE_SERIALIZATION_PATTERN = /^(\d{4})\/(\d{2})\/(\d{2})$/;
 
@@ -29,21 +29,43 @@ function getTimePart(part) {
   return +part || 0;
 }
 
-function parseDate(text) {
-  const isDefaultSerializationFormat = getDateSerializationFormat(text) === DATE_SERIALIZATION_FORMAT;
+function createLocalDateFromUTCTimestamp(timestamp: number): Date {
+  const utc = new Date(timestamp);
+
+  return new Date(utc.getUTCFullYear(), utc.getUTCMonth(), utc.getUTCDate());
+}
+
+function isISOPartialDateString(text: string): boolean {
+  return ISO_PARTIAL_DATE_PATTERN.test(text);
+}
+
+function parseDate(text): string | Date {
+  const isDefaultSerializationFormat = getDateSerializationFormat(text)
+    === DATE_SERIALIZATION_FORMAT;
+
   const parsedValue = !isDate(text) && Date.parse(text);
+
   if (!parsedValue && isDefaultSerializationFormat) {
     const parts = text.match(DATE_SERIALIZATION_PATTERN);
+
     if (parts) {
       const newDate = new Date(getTimePart(parts[1]), getTimePart(parts[2]), getTimePart(parts[3]));
+
       newDate.setFullYear(getTimePart(parts[1]));
       newDate.setMonth(getTimePart(parts[2]) - 1);
       newDate.setDate(getTimePart(parts[3]));
+
       return newDate;
     }
   }
 
-  return isNumber(parsedValue) ? new Date(parsedValue) : text;
+  if (!isNumber(parsedValue)) {
+    return text;
+  }
+
+  return isISOPartialDateString(text)
+    ? createLocalDateFromUTCTimestamp(parsedValue)
+    : new Date(parsedValue);
 }
 
 function parseISO8601String(text) {
@@ -173,6 +195,7 @@ const getDateSerializationFormat = function (value) {
 };
 
 const dateSerialization = {
+  createLocalDateFromUTCTimestamp,
   dateParser,
   deserializeDate,
   serializeDate,

packages/devextreme/js/__internal/ui/date_box/date_box.base.ts

@@ -835,17 +835,26 @@ class DateBox extends DropDownEditor<DateBoxBaseProperties> {
   getDateOption(optionName: 'value' | 'min' | 'max'): Date | null {
     const { [optionName]: optionValue } = this.option();
 
-    return dateSerialization.deserializeDate(optionValue) as Date | null;
+    const deserializedDate: Date | null = dateSerialization.deserializeDate(optionValue);
+
+    return deserializedDate;
   }
 
   setDateOption(optionName: 'value' | 'min' | 'max', value: DateLike | undefined): void {
-    this.option(optionName, this._serializeDate(value));
+    const serializedDate = this._serializeDate(value);
+
+    this.option(optionName, serializedDate);
   }
 
   _serializeDate(date?: DateLike): Date | string | null {
     const serializationFormat = this._getSerializationFormat();
 
-    return dateSerialization.serializeDate(date, serializationFormat) as Date | string | null;
+    const serializedDate: Date | string | null = dateSerialization.serializeDate(
+      date,
+      serializationFormat,
+    );
+
+    return serializedDate;
   }
 
   _clearValue(): void {

packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar.ts

@@ -219,7 +219,9 @@ class CalendarStrategy extends DateBoxStrategy {
       return;
     }
 
-    this._widget.option('value', this.dateBoxValue());
+    const value = this.dateBoxValue();
+
+    this._widget.option({ value });
   }
 
   textChangedHandler(): void {

packages/devextreme/testing/tests/DevExpress.core/utils.date_serialization.tests.js

@@ -107,6 +107,26 @@ QUnit.test('deserializing first date (serialization format is string)', function
     assert.deepEqual(result, date, 'date is returned');
 });
 
+QUnit.test('deserializing year-only string should return correct year (T1323373)', function(assert) {
+    const result = dateSerialization.deserializeDate('2026');
+
+    assert.ok(result instanceof Date, 'result is a Date');
+    assert.equal(result.getFullYear(), 2026, 'year is 2026');
+    assert.equal(result.getMonth(), 0, 'month is January');
+    assert.equal(result.getDate(), 1, 'day is 1');
+});
+
+QUnit.test('createLocalDateFromUTCTimestamp returns local date with UTC components', function(assert) {
+    const utcTimestamp = Date.UTC(2026, 0, 1);
+    const result = dateSerialization.createLocalDateFromUTCTimestamp(utcTimestamp);
+
+    assert.ok(result instanceof Date, 'result is a Date');
+    assert.equal(result.getFullYear(), 2026, 'year matches UTC year');
+    assert.equal(result.getMonth(), 0, 'month matches UTC month');
+    assert.equal(result.getDate(), 1, 'date matches UTC date');
+    assert.equal(result.getHours(), 0, 'hours are 0');
+});
+
 QUnit.test('serialization ISO8601 dates', function(assert) {
     const date = new Date(2015, 3, 5, 6, 7, 25, 125);