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<p align="center"> <img src="logo.svg" alt="cron for Node.js logo" height="150"> <br /> <b>cron</b> is a robust tool for running jobs (functions or commands) on schedules defined using the cron syntax. <br /> Perfect for tasks like data backups, notifications, and many more! </p>

Cron for Node.js

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🌟 Features

🚀 Installation

npm install cron

Table of Contents

  1. Features
  2. Installation
  3. Migrating from v2 to v3
  4. Basic Usage
  5. Cron Patterns
  6. Gotchas
  7. API
  8. Community
  9. Contributing
  10. Acknowledgements
  11. License

🔄 Migrating from v2 to v3

With the introduction of TypeScript in version 3 and alignment with UNIX cron patterns, a few changes have been made:

<details> <summary>Migrating from v2 to v3</summary>

Month & day-of-week indexing changes

Adjustments in CronJob

Removed methods

</details>

🛠 Basic Usage

import { CronJob } from 'cron';

const job = new CronJob(
	'* * * * * *', // cronTime
	function () {
		console.log('You will see this message every second');
	}, // onTick
	null, // onComplete
	true, // start
	'America/Los_Angeles' // timeZone
);
// job.start() is optional here because of the fourth parameter set to true.
// equivalent job using the "from" static method, providing parameters as an object
const job = CronJob.from({
	cronTime: '* * * * * *',
	onTick: function () {
		console.log('You will see this message every second');
	},
	start: true,
	timeZone: 'America/Los_Angeles'
});

Note: In the first example above, the fourth parameter to CronJob() starts the job automatically. If not provided or set to falsy, you must explicitly start the job using job.start().

For more advanced examples, check the examples directory.

Cron Patterns

Cron patterns are the backbone of this library. Familiarize yourself with the syntax:

- `*` Asterisks: Any value
- `1-3,5` Ranges: Ranges and individual values
- `*/2` Steps: Every two units

Detailed patterns and explanations are available at crontab.org. The examples in the link have five fields, and 1 minute as the finest granularity, but our cron scheduling supports an enhanced format with six fields, allowing for second-level precision. Tools like crontab.guru can help in constructing patterns but remember to account for the seconds field.

Supported Ranges

Here's a quick reference to the UNIX Cron format this library uses, plus an added second field:

field          allowed values
-----          --------------
second         0-59
minute         0-59
hour           0-23
day of month   1-31
month          1-12 (or names, see below)
day of week    0-7 (0 or 7 is Sunday, or use names)

Names can also be used for the 'month' and 'day of week' fields. Use the first three letters of the particular day or month (case does not matter). Ranges and lists of names are allowed.
Examples: "mon,wed,fri", "jan-mar".

Gotchas

API

Standalone Functions

CronJob Class

Constructor

constructor(cronTime, onTick, onComplete, start, timeZone, context, runOnInit, utcOffset, unrefTimeout):

Methods

CronTime Class

Constructor

constructor(time, zone, utcOffset):

🤝 Community

Join the Discord server! Here you can discuss issues and get help in a more casual forum than GitHub.

🌍 Contributing

This project is looking for help! If you're interested in helping with the project, please take a look at our contributing documentation.

🐛 Submitting Bugs/Issues

Please have a look at our contributing documentation, it contains all the information you need to know before submitting an issue.

🙏 Acknowledgements

This is a community effort project. In the truest sense, this project started as an open source project from cron.js and grew into something else. Other people have contributed code, time, and oversight to the project. At this point there are too many to name here so we'll just say thanks.

Special thanks to Hiroki Horiuchi, Lundarl Gholoi and koooge for their work on the DefinitelyTyped typings before they were imported in v2.4.0.

License

MIT