Method utc()/format() incorrectly parses the date string 'ddd, MMM D YYYY'
- Dominant language
- JavaScript
- Stars
- 48.7k
- Forks
- 2.5k
- PR merge metrics
- No merged PRs in 30d
Description
**Describe the bug**
If your date string format is 'ddd, MMM D YYYY' than `dayjs.utc()` creates a wrong object, but if you change the format to 'YYYY-MM-DD' it works correctly. Probably it's `format()` issue. Example:
```
dayjs.utc('Fri, Jan 28 2025').format('YYYY-MM-DD') => '2025-01-27'
dayjs.utc('2025-01-28').format('YYYY-MM-DD') => '2025-01-28'
```
**Expected behavior**
This command `dayjs.utc('Fri, Jan 28 2025').format('YYYY-MM-DD')` have to result in `2025-01-28`
**Information**
- Day.js Version 1.11.13
- OS: MacOS
- Browser Chrome 131
- Time zone: GMT+2:00
Contributor guide
Research direction
No file or test is named in the report. Reproduce the two utc() examples first, then locate the relevant parsing and formatting entry points and add coverage for the expected 2025-01-28 result; done means the supplied date string formats to that date without regressing the YYYY-MM-DD case.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- api
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100