at_scheduler

AT event scheduler for Node.js — run a function at a specific datetime.

Zero dependencies. Recovered and maintained by erubboli.

Usage

const Scheduler = require('at_scheduler');

const scheduler = new Scheduler();

scheduler.addJob(new Date('October 27, 2026 11:13:00'), () => {
  console.log('You will see this message at the specified datetime');
});

The scheduler loop starts automatically on the first addJob() — calling init() is optional (and idempotent).

API

new Scheduler(options)

• options.interval — polling frequency in ms (default: 1000). Jobs fire at most this late relative to their datetime.
• options.onError — callback receiving exceptions thrown inside job callbacks. Without it, errors are logged to stderr; either way the scheduler keeps running.

scheduler.addJob(datetime, fn)

Schedules fn to run once at datetime (a Date object or ms epoch timestamp). Each job fires exactly once and is then removed.

scheduler.init()

Starts the event loop manually. Optional and idempotent.

scheduler.clear()

Cancels all pending jobs.

Install

npm install at_scheduler

Tests

npm test

Uses Node's built-in test runner (Node >= 18).

History

First published to npm in June 2011 as at_scheduler 0.1.0. The original GitHub repository (dn2k/node-scheduler) was lost; this tree was recovered from the npm tarball and fixed in 0.2.0:

• fired jobs are now removed correctly (they used to re-fire every tick, while still-pending jobs could be silently dropped)
• a throwing job callback no longer kills the scheduler
• proper module.exports instead of a leaked global
• nodeunit runtime dependency removed; tests use node:test

License

Dual licensed under MIT and GPLv3.