Using latest version (3.6.0) for removing days <div class="snippet-clipboard-conte

subDays adds one hour arround DST about date-fns HOT 1 OPEN

atlanteh commented on June 3, 2024

subDays adds one hour arround DST

from date-fns.

Comments (1)

fturmel commented on June 3, 2024

I believe it's working as intended. Your initial datetime is 3AM the 29th in IDT (midnight UTC), and when doing the minus one day operation we land on the 28th at 3AM IST.

Regarding your linked issue, 24 hours !== 1 day during a daylight saving transition. If you substract 24 hours from your date, you will land on the 28th at 2AM IST.

// process.env.TZ = 'Asia/Jerusalem';

import { subDays, subHours } from 'date-fns';

const date = new Date('2024-03-29T00:00:00.000Z');
const dateMinusOneDay = subDays(date, 1);
const dateMinus24Hours = subHours(date, 24);

console.log(date.toISOString(), date.getTimezoneOffset()); // 2024-03-29T00:00:00.000Z -180
console.log(date.toString()); // Fri Mar 29 2024 03:00:00 GMT+0300 (Israel Daylight Time)

console.log(dateMinusOneDay.toISOString(), dateMinusOneDay.getTimezoneOffset()); // 2024-03-28T01:00:00.000Z -120
console.log(dateMinusOneDay.toString()); // Thu Mar 28 2024 03:00:00 GMT+0200 (Israel Standard Time)

console.log(dateMinus24Hours.toISOString(), dateMinus24Hours.getTimezoneOffset()); // 2024-03-28T00:00:00.000Z -120
console.log(dateMinus24Hours.toString()); // Thu Mar 28 2024 02:00:00 GMT+0200 (Israel Standard Time)