1 files changed, 50 insertions, 0 deletions
diff --git a/packages/frontend/src/utility/intl-const.ts b/packages/frontend/src/utility/intl-const.ts
new file mode 100644
index 0000000000..385f59ec39
--- /dev/null
+++ b/packages/frontend/src/utility/intl-const.ts
@@ -0,0 +1,50 @@
+/*
+ * 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;