I am trying to reset a ISO time to local time, but I am having some trouble converting it.

Currently, I:

// incomming ISO date
let date = new Date('2021-11-08T20:31:23.746Z');

// 1. get timezone offset in hours
const offset = date.getTimezoneOffset() / 60;

// 2. calculate local hour
let localHour = date.toISOString().split('T')[1].substring(0, 2) - offset;

// 3. calculate local time
let localTime = date.toISOString().replace(/[T-:]/, localHour);

console.log(localTime);

// ISO Date
// 2021-11-08T20:31:23.746Z (original)
// 2021-11-08T13:23.746Z (local timezone)

In step 3, I am trying to only replace the first two characters after 'T', however, this is not the correct solution with Regex.

CodePudding user response：

The Date constructor automatically converts the date to your locale after parsing.

// incomming ISO date
let date = new Date('2021-11-08T20:31:23.746Z');

const res = date.toLocaleString().replaceAll('/', '-').split(', ').join('T')
console.log(res)

// ISO Date
// 2021-11-08T20:31:23.746Z (original)
// 2021-11-08T13:23.746Z (local timezone)

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CodePudding user response：

Stop right there and don't do this. Date management is hard. You are going to shoot yourself in the foot. Use a library, for example dayjs.

dayjs(date).local().toDate()