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.
• OCPS 1.0-1.4 compliant: Fully supports the Open Cron Pattern Specification including advanced features like seconds/year fields, L (last), W (weekday), # (nth occurrence), and + (AND logic).
• Works in Node.js >=18.0 (both require and import), Deno >=1.16 and Bun >=1.0.0.
• 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 = new Cron('0 0 0 * * 7').nextRuns(100);
console.log(nextSundays);

Days left to a specific date

const msLeft = new 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

new 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.

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