Parsing does not use a timezone

[melikhov-dev]

Parsing does not use a timezone. Only in format() do I see what I want. It looks a bit weird to me because sometimes I just need a date or timestamp and don't need a format function.

Example

const date = dateTimeParse('2025-01-01T00:00:00', {timeZone: 'Europe/Moscow'});

console.log(date.unix()) // 1735689600
console.log(date.toDate()) // "2025-01-01T00:00:00.000Z"
console.log(date.format()) // "2025-01-01T03:00:00+03:00"


const date2 = dateTimeParse('2025-01-01T00:00:00', {timeZone: 'UTC'});

console.log(date.unix()) // 1735689600
console.log(date.toDate()) // "2025-01-01T00:00:00.000Z"
console.log(date2.format()) // "2025-01-01T00:00:00Z"

[ValeraS]

Currently we use dayjs to parse the date from a string, hence the limitations. dayjs works like this: if the string contains timezone information, it will be parsed to that timezone, and if it does not contain timezone information, it will be parsed to the user's system timezone. Since we do not know whether the string contains timezone information, we can only set the provided timezone to the date object and use it later.

if you know that your strings do not contain timezone information, you can parse them to the desired timezone like this:

dateTimeParse('2025-01-01T00:00:00').timeZone('Europe/Moscow', true).unix() // 1735678800

Work is underway to get rid of dayjs, so that in the bright future we will be able to do this more predictably.

[korvin89]

@melikhov-dev you can follow this rfc gravity-ui/rfc#29

[melikhov-dev]

@ValeraS

Since we do not know whether the string contains timezone information, we can only set the provided timezone to the date object and use it later.

dateTimeParse('2025-01-01T00:00:00', {timeZone: 'Europe/Moscow'});
I think that timeZone param looks weird in this context. So maybe it's better to remove them?