diff --git a/tools/gframework-config-tool/src/configValidation.js b/tools/gframework-config-tool/src/configValidation.js
index 48c1c117..9eb7ddc4 100644
--- a/tools/gframework-config-tool/src/configValidation.js
+++ b/tools/gframework-config-tool/src/configValidation.js
@@ -719,11 +719,13 @@ function isValidCalendarDate(year, month, day) {
         return false;
     }
 
-    if (month < 1 || month > 12 || day < 1) {
+    if (year < 1 || year > 9999 || month < 1 || month > 12 || day < 1) {
         return false;
     }
 
-    const lastDay = new Date(Date.UTC(year, month, 0)).getUTCDate();
+    const isLeapYear = (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
+    const monthDays = [31, isLeapYear ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+    const lastDay = monthDays[month - 1];
     return day <= lastDay;
 }
 
diff --git a/tools/gframework-config-tool/test/configValidation.test.js b/tools/gframework-config-tool/test/configValidation.test.js
index b1d4f59b..a34723f0 100644
--- a/tools/gframework-config-tool/test/configValidation.test.js
+++ b/tools/gframework-config-tool/test/configValidation.test.js
@@ -667,6 +667,10 @@ test("validateParsedConfig should enforce supported string formats", () => {
               "type": "string",
               "format": "date"
             },
+            "ancientReleaseDate": {
+              "type": "string",
+              "format": "date"
+            },
             "publishedAt": {
               "type": "string",
               "format": "date-time"
@@ -688,6 +692,7 @@ test("validateParsedConfig should enforce supported string formats", () => {
     `);
     const yaml = parseTopLevelYaml(`
 releaseDate: 2026-02-30
+ancientReleaseDate: 0000-01-01
 publishedAt: 2026-04-11T08:30:00
 contactEmail: boss.example.com
 catalogUri: /loot-table
@@ -696,12 +701,13 @@ configId: 123e4567e89b12d3a456426614174000
 
     const diagnostics = validateParsedConfig(schema, yaml);
 
-    assert.equal(diagnostics.length, 5);
+    assert.equal(diagnostics.length, 6);
     assert.match(diagnostics[0].message, /format 'date'|字符串格式“date”/u);
-    assert.match(diagnostics[1].message, /format 'date-time'|字符串格式“date-time”/u);
-    assert.match(diagnostics[2].message, /format 'email'|字符串格式“email”/u);
-    assert.match(diagnostics[3].message, /format 'uri'|字符串格式“uri”/u);
-    assert.match(diagnostics[4].message, /format 'uuid'|字符串格式“uuid”/u);
+    assert.match(diagnostics[1].message, /format 'date'|字符串格式“date”/u);
+    assert.match(diagnostics[2].message, /format 'date-time'|字符串格式“date-time”/u);
+    assert.match(diagnostics[3].message, /format 'email'|字符串格式“email”/u);
+    assert.match(diagnostics[4].message, /format 'uri'|字符串格式“uri”/u);
+    assert.match(diagnostics[5].message, /format 'uuid'|字符串格式“uuid”/u);
 });
 
 test("validateParsedConfig should accept supported string formats", () => {