Parsing issue with timezone since 1.10.2

[j0k3r]

Describe the bug
Running v1.9.8:

console.log(dayjs('20170719T112552+0000'))

/*
    d {
      '$L': 'en',
      '$d': 2017-07-19T09:25:52.000Z,
      '$x': {},
      '$y': 2017,
      '$M': 6,
      '$D': 19,
      '$W': 3,
      '$H': 11,
      '$m': 25,
      '$s': 52,
      '$ms': 0
    }
*/

Running v1.10.2:

console.log(dayjs('20170719T112552+0000'))

/*
    d {
      '$L': 'en',
      '$d': Invalid Date,
      '$x': {},
      '$y': NaN,
      '$M': NaN,
      '$D': NaN,
      '$W': NaN,
      '$H': NaN,
      '$m': NaN,
      '$s': NaN,
      '$ms': NaN
    }
*/

Removing the timezone from the source string and the date is parsed again:

console.log(dayjs('20170719T112552'))

/*
    d {
      '$L': 'en',
      '$d': 2017-07-19T09:25:52.000Z,
      '$x': {},
      '$y': 2017,
      '$M': 6,
      '$D': 19,
      '$W': 3,
      '$H': 11,
      '$m': 25,
      '$s': 52,
      '$ms': 0
    }
*/

Looks like the regex (#1307) still need improvement I guess?

Expected behavior
Date properly parsed.

Information

• Day.js Version: 1.10.2
• OS: macOS
• Browser: node 12
• Time zone: [e.g. GMT-07:00 DST (Pacific Daylight Time)]

[chengB12]

still open in 1.10.3

v1.9.7
dayjs.tz.setDefault('America/Los_Angeles')
console.log(dayjs.tz('2021-01-01T00:00:00-0800').format()) ==> 2021-01-01T00:00:00-08:00
v1.10.3
console.log(dayjs.tz('2021-01-01T00:00:00-0800').format()) ==> 2021-01-01T08:00:00-08:00

[iamkun]

will fix soon

[marklai1998]

any update on this issue? I'm still having this issue but only on android device
ios safari and desktop chrome are fine

android chorme 88.0.4324.93 has this issue but not 86.0.4240.198(browserstack)

I narrowed the issue down to the timezone function(remove the time zone and the parsing work again).

ps. downgrade to 1.9.8 doesn't fix the issue

[BePo65]

IMHO the easiest (the right?) solution is to use the customParseFormat plugin with a format of YYYYMMDD[T]HHmmssZ; this will parse the example. If the offset is only optional, then you could use an array with 2 formats: one with the Z format and one without.
Here the code (using dayjs 1.11.2):

import dayjs from 'dayjs'
import customParseFormat from 'dayjs/plugin/customParseFormat'
import timezone from 'dayjs/plugin/timezone'  // just to show the result with offset +00:00

dayjs.extend(customParseFormat)

const result = dayjs('20170719T112552+0000', 'YYYYMMDD[T]HHmmssZ')
console.log(result.isValid()) // true
console.log(result.tz('GMT').format('DD-MM-YYYY HH:mm:ss Z')) // 19-07-2017 11:25:52 +00:00

[j0k3r]

Thanks @BePo65 that workaround is working. But the bug remain :)

[BePo65]

But the bug remain :)

Of course You are right; in the documentation for parse > string it says

Parse the given string in ISO 8601 format and return a Day.js object instance.

And the offset is part of ISO 8601 (see e.g. wikipedia).

So we need to find someone who has the time to improve the regex for parsing the ISO_8601 date 😁

[olekristensen]

Hi there - is there a timeframe before this is merged?
Any help still needed?