Trigger functions or evaluate cron expressions in JavaScript or TypeScript. No dependencies. All features. Node. Deno. Bun. Browser.

Try it live on jsfiddle.

Features

  • Trigger functions in JavaScript using Cron syntax.
  • Evaluate cron expressions and get a list of upcoming run times.
  • Uses Vixie-cron pattern, with additional features such as L for last day and weekday of month and # for nth weekday of month.
  • Works in Node.js >=7.6 (both require and import), Deno >=1.16 and Bun >=0.2.2.
  • Works in browsers as standalone, UMD or ES-module.
  • Target different time zones.
  • Built-in overrun protection
  • Built-in error handling
  • Includes TypeScript typings.
  • Support for asynchronous functions.
  • Pause, resume, or stop execution after a task is scheduled.
  • Operates in-memory, with no need for a database or configuration files.
  • Zero dependencies.
  • Thoroughly tested and is relied upon by well-known projects such as pm2, Uptime Kuma, ZWave JS and TrueNAS.

Quick examples

Run a function at the interval defined by a cron expression

const job = new Cron('*/5 * * * * *', () => {
	console.log('This will run every five seconds');
});

What dates do the next 100 sundays occur on?

const nextSundays = Cron('0 0 0 * * 7').nextRuns(100);
console.log(nextSundays);

Days left to a specific date

const msLeft = Cron('59 59 23 24 DEC *').nextRun() - new Date();
console.log(Math.floor(msLeft/1000/3600/24) + " days left to next christmas eve");

Run a function at a specific date/time using a non-local timezone

Time is ISO 8601 local time, this will run 2024-01-23 00:00:00 according to the time in Asia/Kolkata

Cron('2024-01-23T00:00:00', { timezone: 'Asia/Kolkata' }, () => { console.log('Yay!') });

More examples at usage/examples.md

Feature comparison

In this comparison, we outline the key differences between Croner and four other popular scheduling libraries: cronosjs, node-cron, cron, and node-schedule. The libraries are compared across various features such as platform compatibility, functionality, error handling, and Typescript support.

The table below provides a brief overview of each library's features.

croner cronosjs node-cron cron node-schedule
Platforms
Node.js (CommonJS)
Browser (ESMCommonJS)
Deno (ESM)
Features
Over-run protection
Error handling
Typescript typings
Unref timers (optional)
dom-OR-dow*
dom-AND-dow* (optional)
Next run
Next n runs
Timezone
Minimum interval
Controls (stop/resume)
Range (0-13)
Stepping (*/5)
Last day of month (L)
Nth weekday of month (#)

DOM and DOW?
DOM stands for Day of Month, and DOW stands for Day of Week.