date-and-timeThe simplest, most intuitive date and time library

import { format, parse, addDays } from 'date-and-time';
import ja from 'date-and-time/locales/ja';
import Tokyo from 'date-and-time/timezones/Asia/Tokyo';

const now = new Date();

// Basic formatting
format(now, 'YYYY/MM/DD HH:mm:ss');
// => 2025/08/23 14:30:45

// Localized formatting
format(now, 'YYYY年M月D日(ddd)', { locale: ja });
// => 2025年8月23日(金)

// Timezone-aware formatting
format(now, 'YYYY-MM-DD HH:mm:ss [JST]', { timeZone: Tokyo });
// => 2025-08-23 23:30:45 JST

// Parsing
const date = parse('2025/08/23 14:30:45', 'YYYY/MM/DD HH:mm:ss');
console.log(date)

// Date arithmetic
const futureDate = addDays(now, 7);
console.log(format(futureDate, 'YYYY/MM/DD'));