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;