Submitting Issues

If you are submitting a bug, please create a jsfiddle demonstrating the issue. Note: Before raising a new issue, please do check the existing issues and make sure your issue doesn’t exist.

Read before submitting Pull Requests

Pull requests to the master branch will be closed. Please submit all pull requests to the develop branch.
You will be required to sign a JS Foundation CLA before your pull request can be merged. Sign it right now.
Locale translations will not be merged without unit tests. See the British English unit tests for an example.
Do not include the minified files in your pull request. These are moment.js, locale/*.js, min/*.js. Don't worry, we'll build them when we cut a release.

Code organization

Starting from version 2.10.0 the code is placed under src/. moment.js, locale/*.js, min/*.js are generated only on release.

DO NOT submit changes to the generated files. Instead only change src/**/*.js and run the tests.

src/lib/**/*.js moment core files
src/locale/*.js locale files
src/test/moment/*.js moment core tests
src/test/locale/*.js locale tests

We're using ES6 module system, but nothing else ES6, because of performance considerations (added code by the transpiler, less than optimal translation to ES5). So please do not use that fancy new ES6 feature in your patch, it won't be accepted.

Setting up development environment

To contribute, fork the library and install grunt and dependencies. You need git and node; you might use nvm or nenv to install node.

git clone https://github.com/moment/moment.git
cd moment
npm install -g grunt-cli
npm install
git checkout develop  # all patches against develop branch, please!
grunt                 # this runs tests, eslint and prettier-check

Changing locale files

If you have any changes to existing locale files, @mention the original author in the pull request (check the top of the language file), and ask if he/she approves of your changes. Because I don't know any languages I can't judge your locale changes, only the original author can :)

In order for your pull request to get merged it must have approval of original author, or at least one other native speaker has to approve of the change (happens rarely).

Grunt tasks

We use Grunt for managing the build. Here are some useful Grunt tasks:

grunt The default task lints the code and runs the tests. You should make sure you do this before submitting a PR.
grunt test Run the tests.
grunt lint Perform syntax and code style checks.
grunt release Build everything, including minified files (do not include those in Pull Requests)
grunt transpile:fr,ru Build custom locale bundles moment-with-locales.custom.js and locales.custom.js inside build/umd/min containing just French and Russian.
grunt size Print size statistics.

Note: If the prompt message is Code style issues found in the above file(s). Forgot to run Prettier?, Please run npm run prettier-fmt.

Becoming a moment team member

Moment's team members have extra powers and responsibilities. If you want to become one -- be active in our repositories by answering issues, reviewing PRs, discussing changes, submitting PRs for open bugs. Any help on moment/moment, moment/momentjs.com, moment/moment-timezone will be noticed.

Once you've proven to be trustworthy, submit your request to the gitter chat, and it will be reviewed by the existing team.

Once you become a member:

you can tell your friends
you can close issues submitted by others

But also:

be active in the repositories
pick up work nobody else wants to
attend a monthly meeting
participate in the internal slack group

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