dayjs constructor returns "Invalid Date" in the Browser, but valid date in Node.js
- Dominant language
- JavaScript
- Stars
- 48.7k
- Forks
- 2.5k
- PR merge metrics
- No merged PRs in 30d
Description
**Describe the bug**
In Chrome:
```js
dayjs('11/1/2004', 'MM/DD/YYYY')
// ^ Invalid Date
```
In Node.js
```js
dayjs('11/1/2004', 'MM/DD/YYYY')
// ^ 2004-11-01T04:00:00.000Z
```
**Expected behavior**
The behavior should be the same in both environments
**Information**
- Day.js Version 1.11.3
- OS: macOS 15.6.1 (Sequoia)
- Browser: Chrome 142.0.7444.60
- Node: v22.19.0
- Time zone: GMT-04:00 DST
Contributor guide
Research direction
Start by reproducing the supplied dayjs('11/1/2004', 'MM/DD/YYYY') case in Chrome and Node.js using the reported versions and time zone. Trace the constructor's date parsing path and verify that the same valid result is produced in both environments; add or run coverage for the browser and Node.js cases if the repository provides it.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- web-dev
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100