diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6258805f48..be4e3e09fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@
 - Fix: ファイルタブのセンシティブメディアを開く際に確認ダイアログを出す設定が適用されない問題を修正
 - Fix: 2月29日を誕生日に設定している場合、閏年以外は3月1日を誕生日として扱うように修正
 - Fix: `Mk:C:container` の `borderWidth` が正しく反映されない問題を修正
+- Fix: 誕生日の日付表記を言語設定に合わせて変化するように修正
 
 ### Server
 - Enhance: OAuthのクライアント情報取得（Client Information Discovery）において、IndieWeb Living Standard 11 July 2024で定義されているJSONドキュメント形式に対応しました
diff --git a/packages/frontend/src/pages/user/home.vue b/packages/frontend/src/pages/user/home.vue
index 64b03bc4bc..b721b6487a 100644
--- a/packages/frontend/src/pages/user/home.vue
+++ b/packages/frontend/src/pages/user/home.vue
@@ -94,7 +94,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 							</dl>
 							<dl v-if="user.birthday" class="field">
 								<dt class="name"><i class="ti ti-cake ti-fw"></i> {{ i18n.ts.birthday }}</dt>
-								<dd class="value">{{ user.birthday.replace('-', '/').replace('-', '/') }} ({{ i18n.tsx.yearsOld({ age }) }})</dd>
+								<dd class="value">{{ birthdateString }} ({{ i18n.tsx.yearsOld({ age }) }})</dd>
 							</dl>
 							<dl class="field">
 								<dt class="name"><i class="ti ti-calendar ti-fw"></i> {{ i18n.ts.registeredDate }}</dt>
@@ -161,6 +161,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { defineAsyncComponent, computed, onMounted, onUnmounted, onActivated, onDeactivated, nextTick, watch, ref, useTemplateRef } from 'vue';
 import * as Misskey from 'misskey-js';
+import { versatileLang } from '@@/js/intl-const.js';
 import { getScrollContainer } from '@@/js/scroll.js';
 import MkNote from '@/components/MkNote.vue';
 import MkFollowButton from '@/components/MkFollowButton.vue';
@@ -188,6 +189,12 @@ import { prefer } from '@/preferences.js';
 import MkPullToRefresh from '@/components/MkPullToRefresh.vue';
 import { isBirthday } from '@/utility/is-birthday.js';
 
+const birthdateFormat = new Intl.DateTimeFormat(versatileLang, {
+	year: 'numeric',
+	month: 'numeric',
+	day: 'numeric',
+});
+
 function calcAge(birthdate: string): number {
 	const date = new Date(birthdate);
 	const now = new Date();
@@ -248,6 +255,9 @@ const style = computed(() => {
 	};
 });
 
+const birthdateString = computed(() => {
+	return props.user.birthday ? birthdateFormat.format(new Date(props.user.birthday)) : null;
+});
 const age = computed(() => {
 	return props.user.birthday ? calcAge(props.user.birthday) : NaN;
 });
diff --git a/packages/frontend/src/utility/intl-const.ts b/packages/frontend/src/utility/intl-const.ts
deleted file mode 100644
index 385f59ec39..0000000000
--- a/packages/frontend/src/utility/intl-const.ts
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * SPDX-FileCopyrightText: syuilo and misskey-project
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { lang } from '@@/js/config.js';
-
-export const versatileLang = (lang ?? 'ja-JP').replace('ja-KS', 'ja-JP');
-
-let _dateTimeFormat: Intl.DateTimeFormat;
-try {
-	_dateTimeFormat = new Intl.DateTimeFormat(versatileLang, {
-		year: 'numeric',
-		month: 'numeric',
-		day: 'numeric',
-		hour: 'numeric',
-		minute: 'numeric',
-		second: 'numeric',
-	});
-} catch (err) {
-	console.warn(err);
-	if (_DEV_) console.log('[Intl] Fallback to en-US');
-
-	// Fallback to en-US
-	_dateTimeFormat = new Intl.DateTimeFormat('en-US', {
-		year: 'numeric',
-		month: 'numeric',
-		day: 'numeric',
-		hour: 'numeric',
-		minute: 'numeric',
-		second: 'numeric',
-	});
-}
-export const dateTimeFormat = _dateTimeFormat;
-
-export const timeZone = dateTimeFormat.resolvedOptions().timeZone;
-
-export const hemisphere = /^(australia|pacific|antarctica|indian)\//i.test(timeZone) ? 'S' : 'N';
-
-let _numberFormat: Intl.NumberFormat;
-try {
-	_numberFormat = new Intl.NumberFormat(versatileLang);
-} catch (err) {
-	console.warn(err);
-	if (_DEV_) console.log('[Intl] Fallback to en-US');
-
-	// Fallback to en-US
-	_numberFormat = new Intl.NumberFormat('en-US');
-}
-export const numberFormat = _numberFormat;