Task Scheduling (node-cron)

Task Scheduling

Many applications need to run tasks at specific intervals—like sending weekly emails, cleaning up temporary files, or syncing data with an external API.

Using node-cron

node-cron is a tiny task scheduler in pure JavaScript for node.js based on GNU crontab.

1. Installation

npm install node-cron

2. Basic Schedule

The cron syntax uses six fields: minute hour day-of-month month day-of-week.

const cron = require('node-cron');

// Runs every minute
cron.schedule('* * * * *', () => {
  console.log('Running a task every minute');
});

// Runs every day at midnight (00:00)
cron.schedule('0 0 * * *', () => {
  console.log('Running a task at 00:00 every day');
});

3. Controlling a Task

You can start and stop tasks programmatically.

const task = cron.schedule('* * * * *', () => {
  console.log('Stopped task');
}, {
  scheduled: false
});

task.start();
// task.stop();

Cron Syntax Overview

 # ┌────────────── second (optional)
 # │ ┌──────────── minute
 # │ │ ┌────────── hour
 # │ │ │ ┌──────── day of month
 # │ │ │ │ ┌────── month
 # │ │ │ │ │ ┌──── day of week
 # │ │ │ │ │ │
 # * * * * * *

[!TIP] For more complex jobs involving multi-process concurrency or persistent queues, consider using BullMQ with Redis.