Dayjs Timezone-Safe Date Conversion

import dayjs from 'dayjs';
import utc from 'dayjs/plugin/utc';
import timezone from 'dayjs/plugin/timezone';

dayjs.extend(utc);
dayjs.extend(timezone);

const raw = '2026-10-22T09:30:00Z';

const tokyo = dayjs(raw).tz('Asia/Tokyo');
const berlin = dayjs(raw).tz('Europe/Berlin');
const ny = dayjs(raw).tz('America/New_York');

console.log('tokyo wall clock:', tokyo.format('YYYY-MM-DD HH:mm'));
console.log('berlin wall clock:', berlin.format('YYYY-MM-DD HH:mm'));

const localMeeting = dayjs.tz('2026-10-22 15:00', 'Asia/Shanghai');
const utcInstant = localMeeting.utc();
console.log('utc instant:', utcInstant.toISOString());

const deadline = dayjs.tz('2026-03-08 02:30', 'America/New_York');
console.log('ambiguous local time normalized to:', deadline.format());